At my table, Rod Oakford and Clive Stops bid smoothly:
North East South West
1♦ Pass 1♠ 2♥ (1)
Dbl (2) Pass 4♣(3) Pass
4♠ All Pass
(1) Not pretty to overcall on this hand but the opponents have a likely spade fit, so it is best to get in early.
(2) Described as takeout -ish
West led the ♥A and partner encouraged with the 5, declarer false-carding with ♥J. After a little thought, West continued with another heart.....and that was the end of the defence.
From West's point of view, switching to a club at trick two could be fatal, allowing declarer to throw his losing heart on one of dummy's winning diamonds. In terms of beating the contract, it seemed entirely possible that East had a trump trick (perhaps Qxx or J9xx), while if he instead held ♦A, this was not running away.
Could East/West have done better? Had East played the ♥4 at trick one, discouraging, perhaps West might have found the killing switch - always assuming that he reads the card correctly and not having been from an original holding of K42.
The key point is that West had no real reason to place East with an outside king in addition to his presumed three card heart support to the king - and the reason for this perhaps lies with East's bidding. When North doubled 2♥, East could have redoubled! East would thereby communicate some values and at least tolerance for hearts. Now, after the ♥A lead, a club switch is marked, and the contract goes off.
The Redouble card is perhaps the least used card in the bidding box - time to give it more of an airing!