[Koizumi replies evenly and calmly, still kneeling on Sirius' other side and quietly checking his vitals.] It was obvious that things were about to get much worse, and he is larger and stronger than I am - it was equally obvious that I was not going to succeed at pulling him off you.

I have been trained to properly handle a tazer, and he was and is in no danger from my actions. He's not exactly comfortable, but I am certain he would agree that this is better than the alternative. [Koizumi may not know him too well, but he's very observant, and Sirius is his roommate - the last thing the man needs is another thing to feel guilty about.]