Other than the run-of-the-mill incarceritis, I did have one guy legitimately fake a heart attack to get out of an interview. He wouldn't lawyer up because, in his own words, it would make him look guilty. He was crying and he knew he was on the verge of a full confession as he'd already made several partial confessions. He faked a heart attack to get out of the interview without having to lawyer up or invoke his right to remain silent.
Then ended up pleading anyway. A jury would have slaughtered him, IMO, as he was targeting the elderly.