Can condescending words ever be meant as a joke?

Today we had a costumer who complained about things taking longer than planned and he opened up to me about how he wished he could complain to the big boss himself. Then as I did my best to find an alternative for him, I accidently handed something to him that wasn't meant for him, and he first said "this isn't for me, is it?" and I first thought to myself "dammit, just concentrate!" but then he added "I'm sure you gotta do whatever you do with that".

For quite a while I got a little upset because he didn't even say thank you for me finding an alternative for him, but now I think his smiling says that he wasn't as upset about me as about my co-workers?