It is and isn't - he doesn't know Gabriel's issue, and he will find out later, when Gabriel is returned to him - but it's impossible to separate brothers having spats and trampling over each other's duties. Still, despite their similarities to Lucifer, it's unlike either of them to lash out at each other by going after his brother's pets.

"If you mention one of us by name, we'll hear it and the others won't. Open prayers, all can hear, even to our Father. Conversely you can exclude one in the same way." So ignoring Gabriel was an option as well.