Exactly.
You can disconnect for bathing, swimming, etc.
If she was in the line and did not think ahead, it could have been handled like any other object we forget to remove from our pockets and go on the belt.
If she would have thought ahead, then she could have had the pump in her bag away from the millimeter waves, and avoided most of the questions.
She may have been pat down for the stent that is still in her for the pump to connect to, but that is minor compared to replacing a pump.
Yes, the TSA is a waste of time to the traveler, but as long as you keep in mind that you can't avoid the idiocy, you can work around it and get through the hoops with little to no trouble.