You did exactly the right thing. Play the other guy's set just as he has it set up. Do the best you can. Thank him when your done. Later when they are on break strike up a conversation with the other drummer. If he asks for feedback give him suggestions as to how you set up your kit. If he doesn't ask for suggestions keep them to yourself. If you have future contacts with him you'll probably get a chance to talk more freely and he'll be open to suggestions. Sounds like you handled the situation like a professional.

I agree with Gerald, sounds like you did the right thing.

I was in this exact scenario recently, where I had a gig where backline was provided, there were like a dozen cover bands each playing 15 minute sets, 5 minutes between each. We were 2nd-to-last, and by the time I sat down, the kit looked nothing like when the show started.

Anyhoo, usually I just adjust the seat; raising or lowering height tends to put me in a place where I can reach everything on a kit that's foreign to me. Unless the guy has something really unconventional going, that generally does the trick.

Once, I sat in on a guy's kit that was set up left-handed; but he played right-handed (open-style). That was a true brain twister.

You did the right thing. CHEERS!

You did better than I would have. Of course I play a left hand configuration, so I would have been the ungracious guest and turned it around the right way!

You definitely did the right thing. I've been in that situation a few times and found that other than adjusting the seat and snare height/tilt, it's best to leave another drummer's gear the way it is - especially if sitting in for only a few tunes. Keeps you on your toes though, eh?

I agree, you did the right thing. I was taught early on to be as versatile as possible. I’m right handed and I showed up to a New Years Eve Gig back in the early 90s, I had no time to do a sound check, we went on and I set down to what I quickly found out was a left handed setup. So, quickly I switched the floor tom, hi-hat and snare and played the rest as it was. Different but I made it work. I now practice playing both left and right handed. This is where double mallets come in handy :)

Ya did good... when I'm asked to sit in, I rarely do. I thank the other drummer (or whoever it was that asked me) but politely decline. I really don't care what the configuration is if I do, and would not move the others set up. It's his kit, his gig, and you're just visiting.