An incorrect claim usually leads to a loss for the claimer. But not always: in 'I told you so!' part 1 (here) the claimer profited from his wrong claim.
In his classic The Expert Game Terence Reese describes how an incorrect claim unexpectedly turned out well. Although he was the victim, he saw the funny side of it. (The story below is the last deal of the last chapter —The Vice, The Winkle and the Stepping-Stone — handling about entry-squeezes).

		♠	K 9
		♥	A 10 6 4 2
		♦	Q J 10
		♣	A Q 8
♠	8 5 2			♠	A Q J 10 3
♥	J 8 7 3			♥	K Q 9
♦	9 6 4 3			♦	A 5
♣	10 5			♣	7 4 2
		♠	7 6 4
		♥	5
		♦	K 8 7 2
		♣	K J 9 6 3

South — not Reese's favourite opponent, to put it mildly — became declarer in 4♣ (Reese doesn't give the auction), against which Reese (West) led a spade, his partner having bid that suit.
After taking two spade tricks East played ('a less than dynamic defence') the ♦A and another diamond. Declarer drew two rounds of trumps with the ♣AQ and on seeing the ♣10 drop, half showed his hand, as a sort of claim. East muttered a bit about her outstanding trump, upon which declarer declared that after ruffing his third spade he of course would draw East's last trump.
East now gave in, but not so Reese. Being experienced at doing battle with a jack and a nine as his leading armaments, as he writes acidly (in those days playing bridge usually meant rubber play, in which holding good or bad cards is an item; nowadays we almost exclusively play duplicate bridge, in which holding good or bad cards is irrelevant), he asked South to play on. The reason was that he saw that declarer needed to cross to his hand, to be able to ruff the spade. In order to do so, he could only proceed like this: ♥A, heart ruff, spade ruff, another heart ruff. Next South had to draw East's trump with his own last trump and the diamond suit was blocked.*
Indeed declarer played as Reese had foreseen. After the second heart ruff the situation was:

		♠	—
		♥	10 6
		♦	Q
		♣	—
♠	—			♠	Q J
♥	J			♥	—
♦	9 6			♦	—
♣	—			♣	7
		♠	—
		♥	—
		♦	K 8
		♣	K

Declarer played the ♣K, in order to draw East's last ruff, but what was Reese, West, to discard to this trick? He surrendered.
'I knew they were all mine', said South...

* Of course South shouldn't have played the ♣AQ (assuming he hadn't foreseen the curious squeeze). This is a more logical line of play after winning the fourth trick: ♣A, club to the ♣J, the ♠7 ruffed with the ♣Q, the ♥A, heart ruff, the ♣K (drawing the last trump), diamond to dummy's last high diamond, heart ruff and finally South's ♦K.