I assume when you copied that text out of the browser it appeared as "offline", unless you had an email client that did rich text.
Would have been funny to get a bug email saying it should be "offline" but it's "offline" instead.
I don't think anyone had tried copying it until after I figured out the problem, the bug report would've just been a screenshot.
I was working on a web application with a maintenance mode feature where it would show a "system offline" while changes were rolled out etc. We noticed there was a typo (or so we thought) in the message, so it said "system olffine" instead.
Because this message could be overridden by site admins, there was a somewhat convoluted data flow to produce the final message. I grepped the codebase for "olffine" and found nothing. Then I checked my local DB to see what message was stored - it was spelled correctly. Then I stepped through the backend code to look at the message being returned - still correct.
Eventually I was back in my web browser with the page open on the left (spelled incorrectly) and devtools on the right (spelled correctly). What the hell?
It turned out the problem was that the font we were using had made a mistake with the "ffl" ligature so it rendered as "lff". We contacted the font author and they fixed it.