There was collusion. The State Bank Governor at the time was an honest person, and was not approving his signatures on these loans. Ishaq Dollar had him sacked, installed his personal chaprasi as the Governor.
The lenders cannot go after Ishaq Dar because the money was guaranteed by the State of Pakistan, thus its the Government that's on hook and not Ishaq Dollar. Most of the money was looted by Ishaq Dar and laundered mostly to London and Europe. Why do you think Ishaq Dollar is hiding in London? How do you think his son who has no business and does not work afford to drive a Lamborghini.
Indeed, just look at how beautifully the old men of Pakistan have destroyed the country haha I mean if i were old, i would be hiding out of shame.