argh, i have a coworker who keeps doing things like this all the time. oddly enough, he is an american who has lived here for 20+ years (with the british accent to prove it). the other day, we were meeting and i was in the middle of talking about a project, and all of a sudden he said "that reminds me...a few weeks ago, you sent an email that said something would be 'quite helpful'...i just wanted to let you know that the british use the word 'quite' here differently than americans. when you said something would be 'quite helpful', that was actually insulting. you should say 'extremely helpful' instead". um, REALLY?!?!
This is utter rubbish

Honestly, where do people get this stuff??
As to the OP, it's quite difficult (see what I did there?) to tell the difference between someone being serious and someone "taking the piss". Half the skill of taking the mickey is to look serious but there's normally a wry grin on their face at some point, giving the game away and mickey-taking is ALWAYS meant in fun. If you're really not sure, just ask them, "are you taking the mickey?". Note, an incredulous look on your face will help drive the point home.
Hard to tell without seeing his body language at the time, but this case, however, sounds to me like an insufferable know-it-all who thinks he's being helpful. Sadly, there are people like that everywhere and I've met more than my fair share here. When I first came here, I took people like that seriously, but then, I was very young and desperately wanted to fit in. Now, not so much. You take me as you find me or leave me alone. I have HEARD it ALL. I once went through a spate of giving people a quid if they came up with something original, especially if you could tell they were trying to be obnoxious wankers and there was a big audience. Always did the trick of making them look the knobs they were and me look the long suffering immigrant LOL
Bluntly, my response would have been, "Really? That's awesome!
![2thumbsup [smiley=2thumbsup.gif]](https://www.talk.uk-yankee.com/Smileys/classic/2thumbsup.gif)
" But then, I always was a smart ars* LOL