Maybe it's just me then, I wouldn't boo an opposition player who was genuinely injured. It's okay though, because no one will hear my empathetic silence anyway, so fill yer boots.
You're right about the atmosphere though, it was impressive.
Nope. I'd boo a player if I thought they were feigning injury to gain some sort of advantage. Not if their player going off meant they'd go down to ten men. I might internally cheer a little, but booing doesn't really make sense.