I've been inside a Mir shutter, and as far as I was able to tell, it seemed like any borking from setting the shutter speeds in the wrong order could be deborked by realigning the shutter speeds so they read correctly. I wouldn't bet the life of your camera on that or anything, but if the speeds are now reading correctly and the shutter isn't showing any obvious misbehavior, I think you can consider it borkless unless proven otherwise.
Based on your description, I'm having trouble finding appropriately strong language to use about that second guy. Seriously, he had a customer's equipment in hand and was ignoring that customer's "do it this way or it will break" instructions? That's just mind-bogglingly unprofessional, and plain stupid as well---what if it had been some high-ticket rarity and he broke it for you? Ugh.