Coming from the UK to Aus / NZ I was feeling smug ;) - but of course, this caught me out.
To be clear in the UK the wheel is on the right but the indicator is still on the left side of the wheel as in a European LHD car, just to keep things different.
It's not a UK thing (which side the indicator stem is), it's a manufacturer thing.
Like position of reverse gear on a H-style gear stick, some left-and-up, some right-and-down; some with a collar interlock, some with a button, some you push the whole stick down towards the ground ...
To be clear in the UK the wheel is on the right but the indicator is still on the left side of the wheel as in a European LHD car, just to keep things different.