A Good Fit

A K 4
J 9 7
7 4 2
J 7 6 2
7 6 J 10 9 8 5
A Q 10 8 6 K 5 3 2
A J 10 8 Q 6 3
9 3 K
Q 3 2
4
K 9 5 Vul: Both
A Q 10 8 5 4 Opening lead: 9 of clubs

SouthWestNorthEast
1 1 2 3
4 All Pass

There may be reasons for suppressing knowledge of a major-suit fit from your partner temporarily. Perhaps you're too strong for one bid, too weak for another by your system. Perhaps you want to make an advance cue bid, which your partner will understand when you jump in his suit. But if there's one thing I can say with confidence, it is that if you suppress announcement of this fit one round, you sure want to try to get it in later.
There's nothing more encouraging than announcement of a fit. And there are several problems with not announcing a fit. One is that the next time around, the bidding is too high for you to finally get around say saying, "Pard, I do have a fit in your suit", which seems to have been the factor involved here. A second is that it sounds like a meagre fit, often, sometimes like a "mere preference" if your partner bids a second suit in the meantime.
Could East's cue bid have meant: Limit raise or better? I don't know, but there's no alert indicated. If so, then he's not really suppressing knowledge of a fit. If not, it's a totally pointless bid when East knows of a good heart fit. Through a lot of luck in diamonds (an onsides king, and a 3-3 split), E-W actually have game in hearts.
The opponents would have a good sac at same vulnerability, but they might not find it and even if they do, you've got a better score coming than 4 clubs down 1 -- undoubled. And if the king of diamonds were in the other hand? Then North-South could make 4 clubs, while four hearts would be down one. If doubled, that's worse than 4 clubs making. Well, it's a chance you hafta take, often, but the good major-suit fit should certainly be established to give West a fightin' chance to find the makable game. As it is, the 3 club bid seems like a wasted bid. I don't know what it told West, but it doesn't seem to have been productive.