#8: Did Barry Crane Misdefend This Hand?

At a Sacramento Regional, this was the last hand I ever played against the undisputed king of the match-point players, who was sitting west and partnered by a top player from Denver.  South, misinterpreting partner's 4♠ bid by failing to appreciate that he would have splintered over west's 2♦ with a 4-card spade holding, placed the contract in the wrong strain.

The opening lead was the ♦10, east contributing the queen.  Plan the play.