Does your opponents connection affect your lag in the game?

I never used to think it did but now I'm seriously wondering this. My connection isnt great to start with, but usually playing games is fine w/ no lag. So the game I was just in, started out fine then kept getting the 'your opponents connection blah blah blah etc' message.  Game becomes unplayable and choppy. So I checked my latency in that game and it was over 650!!!!    .....quit the game and its back down to 100.

So either my internet is really fluctuating or that dude brought me down to his level?

bump.