No worries - that same thing happened to my whole band at a huge outdoor festival we were playing...
We all used a tuner none of us were used to, and it was calibrated differently for every one of us!
Trouble is, we didn't know it until the first chord of the first song! It was supposed to be a long slow build-up to an epic huge chord...
Build-up, anticipation... BONNNGGG!!! Train wreck.

Sounded like a kindergarten music class.
Lucky thing is, both guitars dropped out and I carried the song to the end.
So it happens to all of us!
