What sense of responsibility is apparent in Tom and how is this different from the carelessness normally associated with him in The Great Gatsby?
Tom shows a sense of responsibility regarding Daisy's well being after she kills Myrtle, which is different from his apparent carelessness and indifference earlier in the novel.
Based on his behavior in previous scenes, especially when confronting Gatsby, we may have expected Tom to let Daisy get caught and arrested for what she has done. Tom does not do this. Instead, he shields Daisy and soon takes her out of town.
He also deflects George Wilson from the true culprit (Daisy) when Wilson comes looking for Gatsby. Tom says that his act is meant to protect Daisy and himself.
This protective streak is not present in Tom's character earlier, but does suggest something about how he acts under pressure, suggesting also that his true feelings for Daisy include affection.