There are ways a lot of restricted objects can be hidden in a corpse which wouldn’t be caught by any manual pat down of a corpse by the TSA.

I doubt that TSA would stick a corpse at the passenger screening checkpoint onto the conveyor belt for the baggage scanning machines at the passenger screening checkpoint.

I want to believe that this article has its facts wrong about a corpse traveling as a passenger, but stranger things than this have happened at airports and on planes. And the TSA has not only engaged in bizarre stuff at times, it also encounters bizarre stuff too.