I don't understand how some people still think it's possible that they broke up because of his work or that it was amicable, all the evidence you need is in her latest vlog (the one with her asking Charlotte to be her bridesmaid). The first time I watched it I thought it looked like he was angry with her, it was obvious something was going on when she had walk into the bedroom and later on when they had dinner. He seemed pissed about something, she looked as usual. Now it's clear that he was just over her... it probably got to a point where every little thing about her annoyed him (like him tidying the flat and unpacking while she enjoys herself in the park).
It's not an easy decision to make, that's why he didn't stop her from talking to Charlotte that day and uploading the video, he wanted to be 100% sure as there's no going back. He probably made the final decision afterwards.