Slightly off topic but a very similar point.
On a recent flight out of Stansted, a passenger in the row in front of me answered a mobile phone call as we were taxiing onto the runway. I wasn't sure what to do, I thought about trying to summon the cabin crew using the call button but before I could do so the take-off roll had begun and, I figured, there was nothing they or I could now do. He answered a second call shortly after take-off and that time an FA told him to turn it off.
What do the professionals think I should have done in that situation?
(Paracab - I've just read your post properly! I'm not alone it seems.)