wave start mistake

As long as people in the novice wave get scored in their regular age groups, I wouldn't sweat it. 

If there are separate awards for the novice group and you wind up placing, you need to make sure you don't take a podium spot away from a real novice.  I'd think that the RD and timing company could fix that.

I don't know that "novice" necessarily means "slow."  Or even necessarily "inexperienced."  Plenty of people come into triathlon with extensive single-sport experience and lots of athletic ability, but might still sign up in the novice wave. 

But if we assume it does, shouldn't OP expect to be at the front of the wave coming out of the water and through T1, and therefore not have to deal with the "slow, inexperienced" bikers in his wave?  Seems like the only real disadvantage would be having to do T1 in an area that was still packed with racked bikes...

But he'd still have to deal with the slow swimmers, bikers & runners in the age group waves ahead, just like we all have to do in every race unless we're in the pro/elite waves.  I don't see where starting in a novice wave really makes a difference.

But whatever you do, make sure you start in the wave the computer says you're in.  Don't start with your age group unless they've officially moved you there.  Otherwise your time is likely to be F'd up, since the start is usually based on the clock time that the horn goes off and not on your chip.