"I've been on jobs where there's that one actor who is just a miserable, miserable no-good, dirty bastard, and it just turns the whole process sour"

This quote by Joe Pantoliano is describing the negative impact that a person can have on a work environment. He is suggesting that there are some stars who are so unpleasant to work with that it can mess up the whole process. This could be due to their attitude, their lack of professionalism, or their hesitation to comply with the remainder of the group. It is clear that Pantoliano has actually had some negative experiences with particular stars, and he is alerting others to be aware of the capacity for a single person to ruin the entire procedure. He is also suggesting that it is very important to be conscious of individuals you work with, and to guarantee that everyone is on the very same page in order to produce a favorable and productive workplace.