Google Calendar bug

I just noticed this. I'm always logged onto Google. Searching for google calendar, I came across the sponsored link that usually shows up for Google products, this time for Google Calendar. I clicked it, and behold, the browser got caught in a vicious cycle of trying to verify who I am, seeing that I'm logged in, reloading, and trying again. I refreshed the page and tried again. Same result. Is such a problem expolitable?