That kind of people will always find something to jab at. If it's not this it's that. They're very willing to throw such insults as "innocent jokes" but when they're at the wrong end of one they never find it acceptable and will complain till the end of time.
As an example, my first hire was an immigrant from Africa. He can speak English, but his spelling is not ideal - and because English is not his first language his naming structure for things like variable and classes needs improvement. To help with this I implemented specific standards for how naming should work and gave him a ton of concrete examples of how I would name something in a number of scenarios. Now that he’s been working for me for a while, I only actually have to give feedback on naming conventions maybe once a week.
Edit: spelling.