or when they are not in a good mood.
trust me, not matter how good you believe or think your English is, or no matter how much compliment you heard from other Americans (they all tend to do so), your English is not perfect.
Some people get irritated when dealing with people whose English is not good enough or not perfect in their ears, it may be their personalities, also just because they do not have a good mood, do not judge others for what they did once, even to others. do not build enemies in your company if you want to work there long and happy.
try to be positive, ignore the unhappiness that you encountered. explain to your boss what happened, unless this incident affect your current and future career, do not make it a big deal.
these kind of things happen in chinese companies too, you should know if you ever worked in China before, after all, we are just humans.
