Never seen someone banned for speccing out in a 4 v 5. People have done that all the time. Especially if they are on the losing team - they see it as an opportunity to just end that pug and start a new one.

Many people, including myself have specced out during a 4 v 5 and have never been told that was "illegal" to do. Unless this is a new rule or something but it surely hasn't been enforced.