The 2♦ and 3♥ calls were correctly alerted. West's pass over 4♠ was agreed to have been slow.
Result: 5♦X(W)-1, NS+100 (46/48 MPs)
I was called by NS at the end of the hand to question East's bid of 5♦. He said that he had always intended to bid 5♦ over 4♠.
What do you think logical alternatives are for East? What do you think the hesitation suggests?