Sorry, but how on earth is that "an absolutely stupid topic to bring up"?
Rightly or wrongly, when someone says our own actions helped cause atrocities like Monday, then this gives the impression of him giving them some form of justification.
Thought Corbyn struggled overall, albeit no worse than May did. Neill is an excellent interviewer and I've enjoyed seeing him make the two party leaders squirm. Corbyn's main problem tho, in my far from full proof analysis, is that he has allowed the debate back to areas where May feels much more comfortable. He barely mentioned social care.