If its an illegal pass, then they can't return it, since it hit the ground. But yeah, should be 6-7 seconds on the clock. Prob doesn't change the outcome (who knows) but it did hit the ground so no way they can return it. Weird ending, but I think its at least close to fair.
In real game thinking....UTSA should be wishing for the 6-7 seconds to have one last play...but again, 75 yards away....tough for anything to happen...