Manchovie has been late on fixing my guns before (though I actually can't remember any time that he has, I'm sure it has happened.)
Manchovie has also fixed my guns the night before a match with absolutely no prior notice.
He's never messed up my guns before. And he has had many opportunities to manifest any sort of incompetence. He has probably opened up my mechboxes about 100 times. (that's what she said). I will grant that he is a fallible human being and a fallible gundoc and that it is possible that the service to your gun was an anomaly or something. (If indeed it was in the condition you described).
Manchovie has never been unreasonable with me. I value his judgement and expertise. I trust his integrity.
What I can accept in your narrative is the potential that something may have gone wrong. What I can't accept is that his response to you was disproportionate to whatever treatment he received from you.
"He resisted. I asked him to comply."
"Telling him to 'eat it, bitch' is not really a request."