It SOUNDS like you did nothing wrong, but we haven't heard her side. It's funny how things like this can cause hurt feelings. BUT, it IS possible your wife felt that you were basically calling her stupid. Like the man who came out to fix my dryer vent (that was clogged up) and the first thing he asked was if I cleaned the vent filter. Really? Or when I told my husband I heard a peacock and he asked if I knew what a peacock was. Or when I saw a rat and was asked if I was sure it wasn't a squirrel or something else. Questioning my answers is like calling me an idiot.
But at the same time, if your wife put it on you to deal with the salt man, you were trying to do just that and wasn't getting the information you needed to handle that. Reminded me of when my mom would call me at work. Once, she said the kids were playing poop hockey. I guess the dog had pooped in the floor and they were using a broom to sweep it out the door instead of getting a napkin and picking it up. But I was like, what do you want me to do about it from here and did she expect me to leave work and come home. As long as they were getting it up, I didn't care how. Oh and it was her dog. She ended up taking the girls home and leaving my 12 year old son home alone that night.
HELP! I can't stop laughing!!! LOL!!!