I DON'T LIKE PEOPLE MESSING WITH MY PERSONAL THINGS!!!
Haha, in all seriousness, though, knowing that he was going through my personal possessions would definitely upset me. I'm a pretty understanding and forgiving guy, and like to give people the benefit of the doubt where possible, but this would still bother me and make me wonder what else he might have been "going through" while in my place alone. It just speaks to someone's character, especially when they're supposed to be doing a job.
How is he to know which bottles might be extremely expensive or have a lot of sentimental value? What if he sprayed a few sprays of an extremely expensive bottle that had very little left to begin with? Worse, what if he accidentally broke or spilled something by messing around with them. It's an extremely careless, rude and disrespectful action....especially because it's obvious when someone has a "collection" displayed like that, that it's bound to be important to them in some way. Messing with that is without a doubt a violation of personal space and quite likely worse than that. The thing is, it's not that one act that's the real issue, it's the questions it raises about what else is going on and what the person's character is. Basically, again, what else is he doing when nobody else is looking? More power to you if you take it lightly and in stride, but for future instances, I'd personally make sure anything of value was hidden and/or locked up before allowing him to fix anything like that, without supervision, again.