Check out Ken Simons’s Creeping consequentialism and insidious economics, part I over at Prawfs. Here’s a taste:
You are teaching or analyzing legal rule A. Suppose rule A seems to express an underlying standard of undesirable or impermissible conduct C. For example, the legal rule is: "D must pay compensatory damages to P when D’s unreasonably risky conduct harms P." The underlined phrase expresses a norm of impermissible conduct.
Unthinking consequentialism can creep in at both levels of this analysis–in your analysis of what counts as creating an unreasonable risk to others, and in your analysis of whether a legal rule expressing this standard of conduct is normatively desirable. This danger is especially pronounced in analyzing tort doctrine, but it arises elsewhere, too.