♠	A 3			♠	K Q J 8
♥	Q J 10 6 3			♥	A K 7 4
♦	K 10 4			♦	Q J 3
♣	Q 7 5			♣	A 4

¹ EW open four-card majors

To state it as friendly as possible: 3♥ is a safe contract. This is one contract that is not going to be defeated... Critical spirits may however remark that 6♥, bar an unlikely ruff, is cold.
East: 'I think you shouldn't have passed 3♥, it's forcing.'
West: 'I thought it was invitational.'
Who is right, who is wrong?

Solution

East was right, West shouldn't have passed 3♥. West forgot an important rule: 'show invitational strength plus a fit in partner's major at once.'
But East did not raise directly to 3♥ (10-11 points, invitational). He showed his heart support 'via the long way', so the message is that he is too strong for a direct, invitational jump. He shows more than 11 points therefore. On closer inspection: a lot more, since West's 1NT bid showed 12-14 HCP. With 12-16 points (including distributional points!) East would simply have settled for game by bidding 4♥ in the second round; a slam is not an option with a combined point count of 24-30.
So East has more than 16 points! His 3♥ bid is not only forcing, it is slam invitational at least.

East requests West to show controls. After all, from East's point of view both the ♦A and the ♦K could have been missing.
West should have bid 3♠ therefore, control showing. The auction would have developed like this:

Compare this auction — and especially East's 3♥ bid — with a seemingly (!) similar auction here.

Some additions for diehards:
1. East shows at least four hearts, since West's 1NT still only shows four (though five is possible of course). If the 1♥ opening had shown five, East could have bid like he did with only three hearts.
2. Nowadays over West's 1♥ opening many top players as East will bid 2NT: conventional, strong, heart fit. In Europe known as Truscott without the double or Stenberg, at the other side of the Atlantic as Jacoby-2NT. Opinions differ whether the bid is game forcing or can be made on invitational strength as well. (2NT has lost its natural meaning therefore, but that is not a great loss, since with a balanced hand without a heart fit East can usually start with two in a minor.)
3. If East has only three hearts and invitational strength (10-11 points) he is in a fix after 1♥ (if West can have opened on a four-card suit, that is), since he is a heart short for a direct invitational jump raise to 3♥. So he may bid 1♠ then, like here (assumed he has four spades of course).
- If West now rebids 2♣/♦, East can jump-rebid 3♥, showing that kind of hand (four or more spades, three hearts, 10-11 points).
- But if West rebids 1NT, East cannot jump-rebid 3♥, since it is slam invitational, as we have seen. His best bet is then a raise to 2NT. The risk is that West passes with a minimum and five hearts — meaning EW miss the 5-3 heart fit, a disadvantage of opening four-card majors. (A convention like Check-back Stayman solves this problem, by the way).

Read here about a similar — but not identical — bidding sequence in which responder supports his partner's opening suit by way of a jump-rebid.