Well yes, because if I’m expecting such a call, I wouldn’t be doing my shopping. I’d find a nice cafe to sit in and wait. Or, if an urgent call came unexpectedly, if possible I would make my excuses, leave and take the call.
Ah ‘if possible’.
Nobody I’ve worked with has ever taken offence at me saying that I’m in the middle of something and would they mind if I call them back in a couple of minutes when i can be a bit more focussed.
So how do you do that without answering your phone?
If anyone is saying that they would never, ever, under any circumstances take a call while they’re at a checkout then I don’t believe you.