Let’s say the jumpseater is a qualified Delta pilot, going to work, who stops by and politely requests to ride the jumpseat while presenting all required documents. How exactly do you use safety to justify a refusal in that instance?

The CPO isn’t going to be thrilled when they need to give the pilot a PS seat on the next flight for no apparent reason.

Beats me, but for those types that don't want people up there on long flights probably would come up with something. I generally enjoy having the company and tell guys they can ride up front even if there is a seat in the back, their choice.

Same here. I just can’t think of any way to justify that in terms of safety, especially when all requirements are met and all equipment (jumpseat, add’l O2 mask, etc.) is in working order.

Wasn't there a captain the refused another DL pilot the JS during negotiations because he was mad about the contract or something to that effect? What happened to that guy?