OpenID login via Google redirects to standard sign up page (BB-4534)

I was signing up via OpenID (via Google.com) but after authorizing the use of my OpenID for BitBucket it redirected me to what looks like the standard sign up page (but without any css styling); which to me was a bit strange.

I want to use the service but I do not want to create yet another set of credentials to do so. I thought the OpenID route would facilitate this. Please tell me if this is a bug or is it the case that I just have to go through the sign up regardless of using OpenID.