If he wasn't made aware of this restriction so he could bring his own gear instead then I think he had good reason to be pissed off. It's rather clear from the majority opinion here that it was reasonable for him to assume he could use a supplied backline fully.
Bolded for emphasis.
I asked OP earlier if he talked directly to this bass player before the show to be absolutely certain he understood the limitations with using OP's rig. I'm still waiting for my answer, although I'm pretty sure it will be a resounding "yes" in response to the direction this thread took.
Either way, it's just counter-intuitive to offer someone the use of something and then put such a heavy restriction on how it is used. I'm going to assume the other bass player didn't anticipate such anal behavior, didn't bring his own rig, and IMHO was fully justified in being pissed off.