[viveksec]

I think the OP is balancing the economic costs of firing with the psychological advantages to be had by chucking him and clearing his mind. If the guy wasnt "close to indispensible", he'd likely be gone by now. One way out could be to bring some other employees up to speed and then fire the guy.

Overall I agree with the top comment. Having the guy around for long would inflict a negative air at the top that might permeate the entire organization. Gotta go for sure.