Having been a member of CAMRA since before I could legally drink, I can assure you both that bitter is an ale.
Pale ale might not be an ale, if it's an American pale ale, in which case it's a lager.
If the beer is pulled with a hand-pump, with a genuine pumping action (i.e. it's not just a very big tap), then you are buying real ale and it is worth giving some attention to when tasting.
If your workmates are drinking lager in a UK pub then you might want to move desks...

BTW @revisesociology - good post - I don't think I ever got through all of your 8-fold-path posts back in the day, but they did make me think very hard about my attitude tot he universe, as does this.
Thank you!