I have a similar problem with a 40-49 tmap in shadowdale. The dig site is at ~ 0, +1000. There's a shadow treant that spawns within aggro range of the dig site. The shadow treant is yellow to a 48 magician so it is atleast lvl 49, if not lvl 50. A lvl 49 mob in a lvl 40-49 tmap is just unfair when you can draw a tmap with a site that only has lowbie trash get in the way. Unless a greater reward is programmed into the more difficult tmap sites, I see no reason why one site should have a lvl 49/50 mob sitting on the dig site and another shouldn't.
-edit
I think I may have spoke too soon. The treant was easily dispatched by our group and with a 20 min respawn time on it, it's not too bad. I still think its kinda unfair compared to the other tmap locations but it's not as bad as goretusk pathing through your dig site.