What To Do When An Unfamiliar Batman Falls On You. (Don't get between him and his Robin.)
Instead of the pretty manageable cookies explosion he was bracing himself for, Robin barged in the common room to get tackled to the ground by Batman.
Okay, so he was used to that, even if Bruce avoided doing that where Robin's teammates could see it because it was just a little humiliating, and Dick liked to be seen as a strong independent young hero, and not as a sidekick that got tackled around by his mentor.
But then again, having Batman's nice Kevlar cape between himself and the explosion was always appreciable. Plus, Batman had also protected Zatanna, so it all wasn't quite as bad as it could have been.
It was after, when Batman cursed and knelled up, that Dick started suspecting something was really, whelmingly wrong.