Can a Valjoux 7733 be easily or accidentally converted form (30 to 45) or (45 to 30) minutes?

My watch situation

I purchased a watch a few months back and when it arrive it immediately failed, the watch stopped working the crown got jammed. I don't know how it ran before it failed.

Anyways I then took it to get serviced, it’s the first time dealing with this watch maker so I don’t know his skills, I got the watch and I’m satisfied with the watch seems to run as it should chronograph moves etc...

One day I was timing a pizza in the oven (yes that’s what I use my chrono for) and I realized the minute register is moving much faster than it should. Then I timed and tested it with my phone and realize and remembered there are 30 and 45 minute registers on a 7734.

Now the chronograph minute register is not in sync with the dial, the dial says 45min on it but my watch is instead running at 30min. Is it possible he accidentally "converted" it to 30mins during the service, or is it possible the movement has been swapped before I got the watch?

I would like to educating myself before blaming the watch maker, His workshop is in a inconvenient location, so I don’t want to go all the way to him only to find out that it’s not his mistake.