It's been so long since I watched Null's stream on Chloe Sagal, but from what I remember reading the DMs between Wu and Sagal it came across like John knew he was dealing with an unhinged psycho and was trying to end the conversation in whatever way he could to minimise the blowback on him if things went south, which they rapidly did.
Not to powerlevel but I had some personal interactions with Sagal on Twitter before he an hero'd and it was startling how volatile and erratic he was, even by tranny standards, and when you're cornered by someone like that your only focus is how to get away as quickly and cleanly as possible.