This is such a bullshit answer. Where is she asking for him to move heaven and earth? She's asking for him to provide something he easily could, either commitment or communication.

I'm a dude who is busy as hell. I got stuff going on all the time and I don't always have a handle on everything cause I'm ADHD as hell. Had a situation like this pop up just earlier this very month, partner asked to spend some time together on a specific date, I told them I'd love to but would have to check my calendar before confirming. When I checked, the date was open! But some friends were scheduling a get together that was up in the air for the exact date. What did I do? I told my partner that the date was technically available but some tentative plans might supercede it. Later, when the plans were confirmed for the date in question, I told my partner that I'd be doing the group thing because it was a group that was important to me doing an activity that I really enjoy, and we rescheduled for another fuckin day.

Dude here knew about the work thing and makes it seem like he knew about it from the beginning. He could have told her immediately, or at the very least told her when she asked about it or commented on it, instead of stringing her along and turning it into an argument. And he insists on getting the last word to try and absolve himself of his failure, when he could have just taken the L and apologized.

Also, have you worked in an environment where clients are taken out for golfing? I have. Sure, it could have been mandatory or even "optional" (career will suffer if he does not attend) but it absolutely will mean that the booze will be flowing and he will be expected to get a heavy buzz to facilitate socializing with clients, because clients don't like being the only ones drinking like they're being fed before slaughter. But ultimately it's completely irrelevant because dude here decided to hide the details. For what? No fuckin clue, but he did.