It doesn't kick you out, but what they normally do is close the site about an hour before, the session is 50 mins, so it would've expired before the sale starts and you can't buy anything.
If you manage to keep your session alive for when it starts you can sometimes put tickets in the basket but it won't let you check them out.
I guess because there would be more people on for the CL sale, they've let the local ride and not closed it, so if you had a live session then you were just in.