He is one of the well known netcode guy.

But from the few interactions I had with him I would say he is quite abrasive, stubborn and probably somewhat on the spectrum.

But there is a special kind of unpleasantness in writing/debugging netcode for large projects, I don't think you can be agreeable and still you your job correctly.

If anything, in immature engineering organizations, preserving netcode invariants to successfully deliver a multiplayer project might benefit from a little of that disposition.