Does he take both sides at lunch? If so, I'd go ahead and pump so that you don't interfere with that. If only 1 I'm sure there will be enough left even if you pump at 10.
In that case, I would've done 8:30: first, so I'd be comfortable during the meeting and second b/c I'd be more likely to skip a 10 if I knew I'd be doing a feeding an hour later.