I like that Burke wasn't a one dimensional evil villain. He didn't intend to get anyone killed and would have saved everyone if he could. He did want to get the alien for a payday. That's reasonable and understandable. He's the only one that believed Ripley and wanted to verify her story. Ripley acted like an insane crazy woman really when she's just hysterically demanding to immediately launch nuclear weapons at their trillion dollar, decades old colony. With basic enlisted nobody grunts backing her up. Burke was completely in the right and would have been on the hook for everything they did. So it's understandable that he's panicking as everything just keeps going wrong and he can't stop it.