probably because in65 is the original poster’s username on their computer — it would be quite a coincidence if the two of you independently chose the same username.
As for the error output, unfortunately it’s hard for me to tell what exactly is going wrong when all it says is
An error occurred while running scripts from the package “MNE-Python-1.5.0_0-macOS_M1.pkg”
@richard is the expert on the standalone installer, maybe he knows how to get a more informative error and/or debug this?
In the meantime if you just want to get back to work, you could use the standalone installer for the previous release of MNE-Python. There’s a decent chance that the problem is a genuine bug, since the 1.5.0 installer has only been out for 2 days and probably hasn’t been very widely tested yet on different systems.
