Hello and thank you for reporting.
The blocking was very harmless in my opinion, therefore instead of banning him I decided to join the server to see if he still was here, to warn him not to do so.
He wasn't here anymore, but yet still I would not ban for being in front of a doorway when you can jump over him, use !zstuck or even one zombie managed to crouch under him when he tried to block the one trying to jump over him.