If the captain knew exactly what was causing the oily smoke he could have fixed the problem by shutting off the bleed from that engine. He had to evaluate what checklist to use. Electrical smoke unknown source is one which is different than environmental smoke coming from the ACM. He had to make a lot of decisions based on what he knew then, not on what maintenance found after the fact.
I know not everybody is going to agree with one course of action and I have dealt with flight attendants who have a different opinion about how to deal with a situation but that is why they have a captain to evaluate all the inputs and make a decision based on those inputs.