My manager where I used to work did something similar on a much smaller scale. We had a good relationship with a medium sized customer, but their secretary was a pain in the backside. Always finding problems that didn't exist and was very demanding. Anyway, she emails my manager demanding an immediate response to a new problem. He forwards the email to the rest of us. An hour or so later he comes to ask us if we've dealt with it yet, but actually, we never received it and know nothing about it. He'd clicked 'reply' instead of 'forward'.
If that was all, then no biggie. Except he'd added a note:
"Will someone respond to this stupid cow and get her off my bloody back".
Actually it worked out well in the end. He grovelled and apologised, which was accepted and she was fairly subdued. I think it was the wake-up call she needed to realise what she was doing.