The stub on the front of the torque converter is not lined up properly or he has put the trans in without it being seated into trans pump. Tell him to pull trans back out and check that torque converter is in all the way. If the motor is turning over freely without motor obviously trans was not installed properly. Doesnt take a rocket scientist to figure that out. I would assume it is a good possibility that the pump on trans could be damaged at this point but not always the case. I would take it somewhere else if it were me but thats your decision. If he tells you that trans is hydrolocked what else will he tell you(how do you hydrolock an auto trans, it is full of fluid to begin with). Good luck hope this helps