World cricket's governing body the ICC replaced Bucknor, 61, with Billy Bowden after India raged at his mistakes in the second Test against Australia.
Langer told BBC Radio 5 Live: "I feel very sorry for Steve Bucknor, he is an excellent umpire.
"He probably didn't have his best game but for him to be dropped I think is sad. He has been hung out to dry."
Langer's comments come after former Test match referee Clive Lloyd criticised the ICC for their decision.
"You wonder what confidence this gives umpires," former West Indies captain Lloyd told BBC Radio 5 Live.
"What happens now if Billy Bowden makes a few mistakes?"
But ICC chief executive Malcolm Speed said the decision to drop Bucknor made sense.
"If we'd gone on with Steve as the umpire in the third Test I think we'd have had much of the focus on his performance," he told BBC Radio 5 Live.
We can't have one set of rules for the India team and another set for everyone else
Malcolm Speed
ICC chief executive
"The commentators would have been back and forth over every decision he made.
"We've been able to bring a new umpiring team in, we've taken that issue out play and we can concentrate on the other issues that are before us."
Speed also said removing Bucknor took a lot of heat out of the situation.
"If we'd had an all-out fight with the Indian board over the umpiring issue, people would be saying why have we taken such a confrontational approach," he added.
"We've done that in the past many times with the India board.
"My experience of that is it doesn't work, so we've taken a more diplomatic approach where we've put a new umpiring team in. I hope that will work."
But Lloyd, an ICC match referee from 2001-06, said players had to accept that umpires would always make mistakes.
"I don't think anybody is out there to cheat anybody," Lloyd said.
"The umpires I have had, particularly at ICC level, have been excellent. They are people who are very honest and who I trust implicitly.
"Every time something goes against you it doesn't mean the guy is cheating. Nobody is infallible. We all make mistakes - we have to accept it as that.
"That has always been part of cricket - we have to accept the decision and move on."
606: DEBATE
The ICC have allowed themselves to be threatened and blackmailed by the BCCI
Murph73
The ICC initially gave Bucknor its backing to umpire the penultimate Test in Perth but reversed its stance amid increasing pressure from India, who temporarily suspended their tour.
"I am disappointed if any umpire - I don't care who they are - is removed from a position because they might have made a few mistakes," said West Indies manager Lloyd.
"That's not how we play this game. I keep telling people it's still a game, it's not life or death and they have to accept is as such as professionals and move on.
"Cricket will always come first, we always have to accept that. It's unfortunate that this has come in a series that has had a lot of good things in it.
"Cricket is about honesty, integrity and fair play. We have to accept the umpire's decision, that has always been the way."
West Indies Cricket Board president Julian Hunte described the decision to remove Bucknor as "extreme".
In a letter to International Cricket Council counterpart Ray Mali, he said: "What worries us is whether the action of the ICC, in the case of Mr. Bucknor, might create even more problems for the ICC and international cricket down the line."
Lloyd's views, meanwhile, were backed by Australian pace bowling legend Glenn McGrath.
If you're unhappy with a few decisions, you have to be able to handle that and move on
Glenn McGrath
Former Australia bowler
"I think it is sad and disappointing that it gets to the stage where you have a bad game and they're calling for your head," McGrath said.
"I have a lot of respect for the umpires and I think Steve's very good and I've got a lot of time for him.
"What is there, eight international umpires on the panel? And if a couple of teams aren't happy with umpires then all of a sudden you have got one to choose from?
"I think that it's ridiculous. That's why we have the ICC, to control things rather than individual countries."
In the meantime, the Indian team has arrived in Canberra for their tour match against an ACT XI that starts on Thursday.
Source: BBC News
Langer told BBC Radio 5 Live: "I feel very sorry for Steve Bucknor, he is an excellent umpire.
"He probably didn't have his best game but for him to be dropped I think is sad. He has been hung out to dry."
Langer's comments come after former Test match referee Clive Lloyd criticised the ICC for their decision.
"You wonder what confidence this gives umpires," former West Indies captain Lloyd told BBC Radio 5 Live.
"What happens now if Billy Bowden makes a few mistakes?"
But ICC chief executive Malcolm Speed said the decision to drop Bucknor made sense.
"If we'd gone on with Steve as the umpire in the third Test I think we'd have had much of the focus on his performance," he told BBC Radio 5 Live.
We can't have one set of rules for the India team and another set for everyone else
Malcolm Speed
ICC chief executive
"The commentators would have been back and forth over every decision he made.
"We've been able to bring a new umpiring team in, we've taken that issue out play and we can concentrate on the other issues that are before us."
Speed also said removing Bucknor took a lot of heat out of the situation.
"If we'd had an all-out fight with the Indian board over the umpiring issue, people would be saying why have we taken such a confrontational approach," he added.
"We've done that in the past many times with the India board.
"My experience of that is it doesn't work, so we've taken a more diplomatic approach where we've put a new umpiring team in. I hope that will work."
But Lloyd, an ICC match referee from 2001-06, said players had to accept that umpires would always make mistakes.
"I don't think anybody is out there to cheat anybody," Lloyd said.
"The umpires I have had, particularly at ICC level, have been excellent. They are people who are very honest and who I trust implicitly.
"Every time something goes against you it doesn't mean the guy is cheating. Nobody is infallible. We all make mistakes - we have to accept it as that.
"That has always been part of cricket - we have to accept the decision and move on."
606: DEBATE
The ICC have allowed themselves to be threatened and blackmailed by the BCCI
Murph73
The ICC initially gave Bucknor its backing to umpire the penultimate Test in Perth but reversed its stance amid increasing pressure from India, who temporarily suspended their tour.
"I am disappointed if any umpire - I don't care who they are - is removed from a position because they might have made a few mistakes," said West Indies manager Lloyd.
"That's not how we play this game. I keep telling people it's still a game, it's not life or death and they have to accept is as such as professionals and move on.
"Cricket will always come first, we always have to accept that. It's unfortunate that this has come in a series that has had a lot of good things in it.
"Cricket is about honesty, integrity and fair play. We have to accept the umpire's decision, that has always been the way."
West Indies Cricket Board president Julian Hunte described the decision to remove Bucknor as "extreme".
In a letter to International Cricket Council counterpart Ray Mali, he said: "What worries us is whether the action of the ICC, in the case of Mr. Bucknor, might create even more problems for the ICC and international cricket down the line."
Lloyd's views, meanwhile, were backed by Australian pace bowling legend Glenn McGrath.
If you're unhappy with a few decisions, you have to be able to handle that and move on
Glenn McGrath
Former Australia bowler
"I think it is sad and disappointing that it gets to the stage where you have a bad game and they're calling for your head," McGrath said.
"I have a lot of respect for the umpires and I think Steve's very good and I've got a lot of time for him.
"What is there, eight international umpires on the panel? And if a couple of teams aren't happy with umpires then all of a sudden you have got one to choose from?
"I think that it's ridiculous. That's why we have the ICC, to control things rather than individual countries."
In the meantime, the Indian team has arrived in Canberra for their tour match against an ACT XI that starts on Thursday.
Source: BBC News