Also is there any precedent for a minister making such a statement while voting?

Nope. And there still is not; he didn't vote. He abstained.

And how does he feel like he can speak on behalf of government when voting with the minority not only of the house but of his own party? Honk fucking honk?

A He considers his party the government.
B The PM (more than likely) sent him there to do exactly that.