[arbitrage]

You are just wrong. Musicians can absolutely tell the difference between 432Hz and 440Hz. Audience typically can too, although they might not be able to put into words what is different.

Personally, I prefer a brighter concert-A, 444 or higher.

[tripa]

Sorry, that wasn't my point but I haven't made it clear.

432 vs 440, independently of any unit, makes the math easier.

432Hz vs 440Hz, obviously, is two pitches that form an audible interval.

But 432 can be a valuable explaining tool. Just don't read it as Hz, but Hz' (prime), cycles per s', such that 432Hz' = 440Hz.

That's about as far as I'm willing to defend 432.

[Sporktacular]

Doubtful the audiences can, unless maybe they just heard another piece in 440 for comparison. Maybe those with good pitch memory would notice something before they readjusted. Maybe.

[OscarCunningham]

The pieces they used were John Williams movie soundtracks, so I can image that they were very familiar to some of the audience.