No other company would grant them more than 2 months chargebacks, there's no reason why you should either.
The only problem is - how far back will his CC company let him go? I've heard stories of porn customers going as far back as 15 months (funny how the CC companies will allow more than 2 months of CB's to porn customers, and not anyone else....). If you run a risk of shooting yourself in the foot with a higher CB rate, it might be worth it to pay him just to prevent that.
(and start using more checks processing......
)