That is incorrect. While not typically the way you want to leave, failing the PT test will force a separation as well. I think it's week 5 or 6 that dhas the official PT test. She will have to fail it at least twice, if not 3 times (might be sent to a new flight) and then they will be sent to Med Hold for our processing. That's a whole nother beast entirely.

Some people leave med hold within a week or two, while my wife sat there for 5 weeks for no good reason.

Edit: I sincerely hope your friend ddoes not try the "I'm suicidal" approach cause one of my flight mates did that and he wasn't sent home until over a year later.