What he said was "Double is almost always suggested by a hesitation in a potential sacrifice situation".
The demonstration he gives is "...because it says 'hey partner, whatever you were thinking about, go ahead and do, you're safe.' "
Whether that is sufficient for you is definitely something to discuss, but it's a very common argument, and usually is considered as holding water.
Now, assuming we're going with that argument, there are two paths that we go down:
- Pass is clearly Forcing (whether because it's Obvious to All A Players, or clearly marked in system notes, or whatever). Now, the UI from the hesitation is "I don't know what to do here, partner" - but "Pass" says "I don't know what to do here, partner, you pick". So - there shouldn't be a disallowed LA.
- Having said that, there's been an argument forever about whether "pass-and-pull" is stronger or weaker than immediate action. And the argument I find persuasive was from the EHAA book: Weaker is theoretically better, but gets rolled back on the inevitable director call when partner hesitates before the "forcing" pass, or when decider hesitates before doubling. Stronger wins the TD call much more often.
- If this isn't a FP situation (and the one in the OP doesn't seem like "obvious to all", unless there's a whole ton of meaning to West's calls I don't know about) then we're in Gilithin's world: "Pass is possible by system, but partner wants to do something; doubling is a good way to say 'partner, whatever you wanted to do, do.' " And we go down the path:
- Is Pass an LA? If so, "the hesitation clearly shows interest in something other than defending 5♥ undoubled."
- If not, is 6♦ an LA over double? It doesn't have the "whatever you want" issue as it's hard to defend 5♥ any more...but is it reasonable? And does it score worse than 5♥x?
I don't know where I sit on the "double in face of a 'make a forcing Pass by hesitating'" argument. I'm not going to throw it out of hand - because yeah, double does allow for "whatever you wanted to do, do". But I'm not in "we can (bridge-)never allow double", either.
When I go to sea, don't fear for me, Fear For The Storm -- Birdie and the Swansong (tSCoSI)