I noticed that too, there's a couple dozen random transactions that happened after the ICO ended. I'm guessing these are one-off transactions for things like bounties, or maybe last minute sales that didn't go through properly due to network congestion that the team is fixing up.

As for burning the remaining ROCK2, they're probably waiting to fix any straggling transactions (as mentioned above) before they burn it all. Doesn't really matter, it shouldn't affect the final price since it's now inaccessible to the public.