Salty. Probably the guy didn't know how to articulate "bitter" or any other number of flavors. But I know about the negative comment bugging ya. One can have 99 people tell them what a badass job they're doing and then latch onto the single poor response.
I feel this same way about playing music live. I have super high expectations for myself, so when I screw up, I can't help but think that every musician in the crowd notices. And it's only them that notice too, usually. Played a show on Saturday, crowd was way into it, but I played shaky in the first song, only a couple people maybe noticed at all, but still I can't get over it...fixated on the small, negatives...