if its still running now then, it probably didnt hurt anything that bad. but are you sure that he just drained the tank or did he maybe disconnected the gear as well?
nope, he left it all hooked up, because every once in a while i get lazy and just throw some oil in there and a frash tank of 93 and it drains the oil in a few days
When you are done, and before you install the front oil cover, use the stock rubber grommet that the oil injector lines ran through. Put some black silicone where the grommet meets the case, then fill the holes with silicone.