One of the PIC's biggest responsibilities is risk management...considering all information, past experiences, and written guidance in order to best manage the risk to the airplane, passengers, operation, and crew's certificates.

To me, it sounds like that's exactly what this captain did.

Yes, at times your decision may differ from dispatch or management...but they're trying to run an airline and you're trying to get an airplane full of people that you're responsible for safely from point A to point B.

Kudos to this captain for leaving the parking brake set and risking his job for what he thought would provide the best and safest transportation for his passengers.