Some airlines include the weight of a jumpseater in the BOW of the aircraft. Some airlines don't. Some have policies that prohibit the bumping of certain pilots from a jumpseat (ie, the jumpseater is going, the aircraft will have to lose weight somewhere else to accommodate the weight of the jumpseater). These are all very dependent on the individual carrier's policies, as well as the CBA of the pilot group.

The PIC of the aircraft is the final authority as to the operation of the aircraft. If you are faced with an issue regarding jumpseating that you are unclear on, the PIC should always be consulted.

I see you're a DL pilot. If this was a DL flight, contact your Jumpseat guy.