By now, you can expect Psych to be unrealistic. In the real world, Shawn would be fired for illegal searches, people would hate him for how selfish he usually is, and he’d get in a lot of trouble for hiding a polar bear. Since this is fiction, anything can happen, so serious incidences become manically comical.
“The Polarizing Express” is the Christmas episode and is very funny in spite of how mean Shawn is. In his mind, everyone would be in terrible places without him, but the upside is that we see each characters in wacky situations. There’s a crime and Christmas stuff shoehorned in there, but the episode is about Shawn and his imagination.
“Dead Bear Walking” is nearly as silly, with Lassiter’s sister filming the proceedings and a polar bear on the loose in Santa Barbara. Lassiter comes off as a bigger tool than usual with his pompous attitude, but the case is cracked in the end.