NO it is big deal for me so I HAD to check it since you aroused my curiosityI don't find it a big deal. If I were to make the decision I wouldn't have let the highest ranking air force officer fly alone either. The back seat does point towards the ACM being just a passenger but then the manoeuvre itself wasn't a walk in the park to take upon one's body, let alone a senior one such as the ACM's.
Like Windjammer said, the previous ACM's have flown in 2-seaters as well. Although, at least ACM Tanvir Mahmood Ahmed and ACM Rao Qamar Suleman used to fly in the forward seats.