Hmmm...thats sounds a tad gay!!!! When you refill the MZ open the oil filter bleeding screw, then tick it over untill oil pumps out of the bleed screw situated at the top of the oil-filter casing. Once oil has pumped through nip the screw shut and turn bike off, let it cool down then top her up, run her for a couple of minutes, let her settle and check level, adjust accordingly. Sounds like he just topped your bike up and didn't check the level after final fill!!!!! If topped up too much you shouldn't do any damage, you might get a blown seal somewhere, did you check the level with the engine cooled down? If it was hot the level will be higher, also check your air filters not sopping wet with oil, that happens when overfilled. Its easy to overfill the Baggy, a little top up can push the level a lot higher than expected!