This has happened to be a few times. I guess a bot check must be generated when an action is taken, after the action not before. So on your next forge or fight attempt, you'll see the challenge. The problem is if you go away for a few minutes and come back and try to do something, then you get told you failed a bot check and have a one hour ban. Having never seen a bot check screen.
What just happened to me was I did a bunch of fights, happened to click too fast so I got the message about only one fight at a time. I went to do some other things for a couple minutes, came back and hit fight again, and was under a ban.
I'd like to suggest the botcheck 2 minute timer start when the first challenge page is displayed, not when the botcheck is generated internally. This way you are guaranteed to at least see it once before getting a ban.