Callous is, like, not letting him play ball with you or ignoring him. Not tossing him off a roof!
As I look at it 12 hours later, I am also struck by the use of the word "chuck." Kind of like tossing an empty Skittles bag into a trash can.
The authors, Matt and Joe, must have been yucking it up trying to outdo each other with clever phrasing while they wrote this after a few beers for Saturday lunch.