I just created and merged a PR as someone else - but logged in as myself

I have in the past half hour modified the branch permissions on a private repo (cloud bitbucket) to allow only myself to merge.

After this I commited some work and created a PR. This I merged and that all went fine. This was from a bugfix/ branch to develop.

Then I created a PR from develop to master and merged it. After the merge I noticed that was all done as a colleague.

How?

How was it possible that actions that I did were done under a colleagues name? According to the merge commit, he did it. But it was me.

In attachment, I'm the Deadpool pic (red/black) and the colleague is the teddybear looking avatar. I (deadpool) created commit 64b5331 as both the creation and the merge of the PR.