If you put it like that it certainly looks like it, and first off, I don't think we have enough evidence to know if Rush is really as ambiguous as he sometimes, as in this situation, appears to be, or if we are indeed getting the wrong picture.
That being said, I think Rush was much much more afraid that if he'd consulted TJ, she'd tell Young. Or if he told too many people of it, that Young would find out. And personally I think if other people hadn't be around when Young walked in the lab, he would have shot Rush, knowing he had a tracking device. I trust Young much less with moral values like this than I trust Rush with them.