Alright, all is good. I pulled off the right fork as well to change oil (trying out 7.5w). As soon as I pulled the top cap off and let the piston drop, the right fork did the same thing - recessed area came out slightly beyond the seal. So it seems that I was correct about the piston holding it all back. No leaks on the left fork after about 15 pumps. Wooooo. Also swapped out guards for gaiters, will see how it all goes.

PS. Like my center stand?