+1.
I had the same problem, and it healed itself.
Most likely the seal wasn't lubed when it was installed at the factory, causing the first seepage. When the mechanic replaced it, he most likely repeated the error. Give it a while before you take it back to your dealer. If the problem persists, clean the area well, run the bike normally, and after each run check the seepage to see where exactly it's leaking. Is it around the kick start shaft, or from the edges where it meets the case?
There are several reasons the seal could be leaking, but most likely it just hasn't broken in yet.