Playing for down one

In an online bridge mini-tournament Sunday evening, my left-hand opponent opened 3♦ Pass Pass to me. I held:
♠A 7 5 ♥A 10 9 3 ♦9 7 ♣K Q J 5.

After I made a takeout double, partner basically located our heart fit and drove to slam. Right-hand opponent doubled -- oops.

West led the ♦K, and these were all four hands:

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

Yes, we've overbid, but when playing online in a short match (12 boards), you have to go for it. It's pretty much potluck (as is the IMP Pairs at the NABC, by the way, for similar reasons).

I knew (from the Lightner double) that RHO was void in diamonds, so the contract was hopeless. Could I hold it to down one? I played the ♦A and East ruffed and exited with a low club, my ♣J taking the trick. Now it was easy to draw trumps and lead up the the ♦J. That was a discard for my losing spade (after I took the finesse for the king).

Deep Finesse says that East-West can set me two after I play the ace at trick one. East can exit with a heart or one of the spade intermediate spots and I can't develop enough tricks.

To hold it to down one, I need to give up on making it and duck the opening lead. If West continues with a diamond (a shift isn't any better), I can duck if it's a low one or play the ♦J if he leads the 10.Let's say East ruffs (discarding isn't any better). If he makes the safe heart exit, I can draw trumps, ruff a club, and take the spade finesse. Let's say he covers it (ducking works out the same).

I can now ruff a second club and cash the ♦A to discard a low spade. When I lead the ♦5 from dummy, this is the position:

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

East is squeezed in the black suits.

[There are offshoots of this line of play (depending on whether East covers the ♠Q or not).]

For down one, we scored minus 9.82 IMPs. Down two doubled was minus 13.10 IMPs, so it could have been worse.

When I looked at the results later, I wasn't surprised to see that nine pairs went set in 6♥. I was shocked, however, to see that 10 pairs went set in four!! You can all the results here.