Annoying but not so bad. Just transpose up the fret number the capo is on, unless they are down tuned and didn’t tell me. I might suck at guitar but learning it has at least helped me identify what a less knowledgeable guitarist is doing.I had a similar problem once, a long time ago. Guitar player had no clue about theory and no ear - he'd sometimes play a major chord when it was supposed to be minor and couldn't tell something was off.
"What chord are you playing?"
"I'm playing a G."
"Yeah, but you've got a capo there. What key are we doing this in?"
(Unsure where to put the capo, tries to remember where it was last time, asks others). After a while:
"Ah, got it. It's there."
"So, what's the key?"
"It's a G chord."
"Yeah man, but you've got a capo on there, it's not really a G chord anymore."
"No man, look at my fingers: It's a G."
"Dude, I'm not interested in how you arrange your fingers on the neck, I want to know WHAT CHORD IS GOING TO COME OUT OF YOUR AMP!"
"...I'm playing a G."
I felt like I was caught in the classic "Dave?/Dave's not here." loop.
Whats rough is when they tell you a key and it’s completely wrong.