This happened to my partner and me yesterday, and I'm still rankled. At trick 6, my partner made a good claim: he described that he'd finish pulling trump, concede a heart, and the rest were good (and wrote that out in the claim description). The opponents rejected the claim, so partner drew the last trump and conceded a heart. and then, instead of ruffing back in and taking the rest, he misclicked and gave the opponents an extra, undeserved trick. After the hand was over, he appealed to a TD, who adjusted the score to what it should have been (since partner had already claimed, it was obvious what he intended, and he argued that in the club he'd be able to replace a card he pulled by accident and play the card he intended). Then, the opponents appealed to a more senior TD, who said that there are no undos for misclicks in this tournament, and adjusted the score back.
I feel slightly cheated. It appears that an effective, if unsportsmanlike, tactic is to reject every good claim, even if you can see that it's good. If the opponent plays it the way they described, you've lost nothing. If you run out of time, you get the double-dummy result and have lost nothing. If the opponent misclicks, you've gained something you wouldn't be able to get otherwise.
Is there any downside to always rejecting all claims? I want there to be, because this goes against ACBL law 74B.4 on etiquette ("As a matter of courtesy a player should refrain from... prolonging play unnecessarily (as in playing on although he knows that all the tricks are surely his) for the purpose of disconcerting an opponent"). Should I just accept that the laws of bridge are slightly different online, and start rejecting all claims because it's at least as good as accepting them?
How should I handle this situation next time? (Yes, I realize that "don't misclick" is the best solution. but the result we received still feels unfair.)