With all due respect, you seemed to have arrived at a conclusion regarding the Captain. As someone as equally interested in safety in tight, obstructed, congested operating areas there are numerous questions that should be asked before drawing a conclusion to truly arrive at a solution.
1. Was this the first time Capt operated at your gateway?
2. Just because it looks flat, slope can definitely affect power required to move a plane in a turn, etc. When I was an F/O I didn't really notice the slopes until I sat in the left seat and realized the challenge.
3. Was it a single engine taxi (if so, perhaps a company note to say "No single engine taxi leaving ramp.."
4. Does the operating manual have power limitations for taxi? Ours do, and the F/O has to back up the Capt whose eyes are outside and cannot always tell they are exceeding the limits.
5. Do you have a tug available for the situation that the plane gets 'stuck' leaving a congested ramp so unsafe levels of power are not needed?
6. Should a tug be used to back all aircraft up at your station and position for safer ground/ramp ops?
7. How many similiar incidents at this gateway regarding this type aircraft have been reported? Other aircraft types?
8. Was the aircraft late for departure?
9. Did flight have a departure clearance limitation?
10. Does your operation include a 'ramp brief' outlining personnel locations, identified concerns (heavy weight/ice/contamination, etc)? IS it located in the company gateway notification?

Could go on, but simply drawing a conclusion based on perceptions will not arrive at the safest solution. Perhaps your conclusion is correct, but I am more concerned for the long term safety to arrive at a fact based, detailed operations view of the ramp environment and the metrics that affect safety and good business productivity/efficiency.