I know RETURN .T. works fine, but RETURN (.T.) also seems to work OK.
Since the parentheses indicate a named expression, I'm not sure how well this will work in the future. It's an easy global search and replace, so if you want to change them all, you might as well.
New can of worms: A plain ol' RETURN also returns .T., so you could use that.
Insanity: Doing the same thing over and over and expecting different results.