I am pretty sure there is something more to the story that we are missing. Without hearing the other side of the story, there is not way to conclude the etiquette here.
Some of the possibilities (wild assumptions at this point, since we probably may not ever hear the other side of the story, since OP's opponent is not in this forum). I will refer to OP's opponent as B and OP as A.
1. Did B think the "fault" call on first serve was too delayed? Essentially accusing A of trying to return the serve, and calling it "fault" when the return attempt was ineffective ?
2. Did B think the "fault" call was absolutely wrong and a cheating attempt ?
3. Did B think A was purposely trying to delay the point?
I mean did A check his cell phone on the way back to baseline after clearing phone, or chit-chat with someone on the next court or took a drink .. or just walking really slow ?
4. Is there any previous history between A and B ? Did you guy play before? How was that match?
5. Was B infact giving A the pont ? A mentioned the score he called was "love 15" which mean B awarded A the point. Again if that was the case why?
There is something totally fishy about the whole story, and outcome, and just trying to figure out the missing pieces.
What I am 100% sure is that, since B had been playing tennis for sometime, B could not have done this to everyone else (there would be too many issues enough to change his behavior otherwise). So there is definitely something more to the story.
The ball was out by a couple inches. I took a couple steps and a couple seconds to move over to the ad side and move the ball. He didn’t look up & served while I was on the other side of the court. I think he should have served his second serve again.
This was the first point of the game. I was ready for the first serve on the deuce side It was a couple inches long so I hit it. It rolled in the middle of the ad side. I gestured & took a couple steps to move it out of the middle of the court ( no question about being unsafe). While I was on the ad side he apparently didn’t notice where the ball was, where I was or that it had to be moved. He served without looking to my side then moved to the ad side.
I'm trying to picture how he could serve without noticing where the ball landed and that there was no returner present.