Listen closely and believe them
Mort Sahl, a Canadian-born comedian and satirist, said, “A conservative is someone who believes in reform. But not now.”
Today, look only at the West hand and the auction. What should West lead against six hearts?
Sometimes, your opponents might be blowing smoke screens in the auction, but very rarely. Also, if they do and are successful, they deserve congratulations. Almost everyone, though, is trustworthy.
Notice that East, facing a passed partner, made a weak jump overcall despite holding a four-card major.
To be honest, given the prevailing vulnerability, I think East could have bid three diamonds. Then over three hearts, West could have jumped to five diamonds. Sock it to ‘em, baby! Five diamonds doubled would have been down only three, minus 500.
In this auction, South’s five diamonds showed a first-round control in that suit (ace or void), interest in a slam in hearts and, in principle, no first-round control in spades, a suit skipped over.
Given that, West should have led a spade, presumably the 10. Agreed, North ought to have had a spade control for his jump to six hearts, but it probably wasn’t the ace, because he failed to control-bid five spades. As you can see, this lead should have resulted in six hearts down one. Also, yes, if he could have seen all of the cards, West would have led the spade king!
In a duplicate, every table except this one was in four hearts making seven when the lead was a diamond.
What did West lead against six hearts? The diamond queen, of course!