mathy,
The typical cabin altitude of a jet in cruise is 8000', not 5000'.
This and other things in your post indicate you don't know what you're talking about, so perhaps accusing others of a wind-up might be a case of fighting above your weight....
Furthermore, mobile phones shall be switched off/in flight mode from the time the doors are closed to the time they are open. Ie sensing the takeoff roll might be a tad late...
Not under everyones Regs. Under ours it's push-back till the on board system is switched on, then TOD till touch-down. Not everyone has the same rules.