Originally Posted by corporate-wage-slave

If it's his smaller bag, and gets a yellow tag, then it is guaranteed to go with him. If it's his only bag then he can volunteer for the yellow tag.

I have to say in my last 100 flights (excluding the Embraer services), and I'm usually in row 1 so I can see this, I can think of perhaps 2 occasions when hand luggage was sent to the hold at the last moment, and with the full agreement of the passengers concerned. Some cabin crew have never had to do it. That's not to say there isn't some last minute awkward reshuffling, crew bags off to the flight deck, pillow bags taken off, wardrobe used, unused middle seats deployed - you name it - but generally it all fits in the end. That's just my reality.