O360 Oil Leak around Exhaust gasket during break-in

[Pilot-To-Be]

So we just got our O360 overhauled, installed and the first 10 hours have been put on it. After the first flight, everything looked perfect except for a slight oil leak around the number 2 exhaust gasket and a little dripping down the exhaust pipe below the gasket. I can wipe it up around the gasket in about 5 seconds, but I’m stumped. My mechanic says it’s oil that’s still getting past the rings as he doesn’t think they’re fully seated yet, but that doesn’t make good sense to me. why only on one cylinder and not the others? Do I need to keep running it at 75% and see if it stops, or is there an issue with the cylinder? The oil consumption is virtually zero, so how much longer do I need to be in break in mode?