[user104658]

Originally Posted by Ammi

...the Queen isn’t inferring that anyone is ‘lying’, we all know that there are many truths and that they often vary...no one is going to stand up and say...’yes, I’m racist...that would be me, hello there...’...’recollections may vary’ is a version of no comment...

I personally think “recollections may vary” may in this case be a reference to, for one, context (she’s suggesting that it wasn’t meant the way they’ve taken it) and for two... should be taken with the view that she probably was not there herself during this conversation. She’s heard what Harry has said and has asked the accused family member what was said and they’ve given a different version. So she can say “recollections vary” i.e. she has heard different accounts of what was said, but she wasn’t there so isn’t necessarily calling either a liar, just pointing out that she doesn’t know first hand.