The 2♠ call was explained as 'natural, at least 4 spades' when North asked after it was passed around to him.
North expressed considerable doubt that 2♠ was actually natural and asked several follow up questions as to whether it might in fact be a cue-bid, and what other options East had.
When North turned out to have psyched the 1♠ call, E-W were not amused. 4♦ was not a success, while 4♠ would have been fine, had North not talked E-W into believing that perhaps they had a misunderstanding.
How do you rule?