How did the doctors revert them?
My point is the operation was so unique that there was only that one doctor that was able to perform the surgery. So if Castor Troy killed him, burnt everyone else involved as well as the research lab and notes, how was it that regular doctors were able to revert them back?
The doctor said at the very beginning, "you don't know what I can do" meaning he was the only that was able to pull that body switching surgery off.