Thats not really a great solution, and no offense to you. You essentially have a BOT that is easy to farm, however, in the few instances that the BOT sticks with someone, or someone follows the BOT around, it can still deal damage. So lowering the reward for a slain BOT, is basically like have a free CREEP for the other team that has abilities, flag capture ability, and item usage.
I think a way to fix the BOT issue is as soon as the player leaves and a BOT takes over, the BOT is given 8,000 gold, and upgraded to Nightmare Difficulty. That way the BOT now may equip itself better, and is gathering gold faster then the players so it stands to be a semi-threat. Just a thought. But by decreased the amount of reward for the BOT, it makes no sense.
IMO The best solution is to remove the AI Teammate as soon as someone leaves the game.
- Mord