Bonnar has a chance. Not a good chance but a chance none the less. As the clip shows he has nothing to lose from this fight and that is a dangerous aspect.
Bonnar has given some decent fighters tough fights(Evans, Jones, Griffin) and he has looked pretty good in his last few fights. He will come forward 100 miles per hour and he has never been stopped except by cuts. He isn't going to mentally fold like Griffin did and he will try to make the most of this opportunity.
This chance is exactly like Rocky vs Apollo 1 and I wouldn't even be that surprised to see it go somewhat similar to that fight(Apollo beat Rocky up pretty good early and got the win in the end but Rocky hung in there and made it close).