Reading back altimeter settings?

Paul Tomblin wrote:

Does anybody have a good handle on when ATC wants you to read back
altimeter settings? On a single IFR flight on Tuesday, I encountered
several controllers who I'd check in with, and they'd give me an altimeter
setting, and that would be it, and 2 (both in Canada, BTW) whom when I
didn't read back the altimeter setting gave it to me again.

Maybe the way to think about this is how it would affect the analysis of
an accident. Suppose you flew into a mountain, the question would be
whether you had your altimiter set correctly. So they play back the
tapes and found that you readback the setting -- that takes the
controller off the hook because he got the message through to you.
Otherwise, somebody my try to say the controller should have tried one
more time...