Well, 10% was a rather rounded up, I didn't want to sound really nerdish by quoting the speeds we use at work (oh, we have sodding guidelines even for this!). But actually, you'd be surprised how much time compression does go on. And believe me, it's more than 4%. Producer/director Sean Cunningham is a big believer in it (not that many of his movies are particularly good) and he actually speeds up his footage by 8-10%. Seriously, he does. You can hear that from the horses mouth, and also from the poor directors whose footage he's speeding up who don't want it done!
10% sounds a lot, and obviously not all footage will handle it, but I have no reason to believe just enhancing the speed of Ben's twirl a bit isn't feasible.