They were in a Walkabout. Of all the pubs in Birmingham, David Warner and Joe Root opted to go to an Australian-themed bar which uses the slogan: “Home of the awesome spirit of Australia.”
This makes Warner look like a homesick child, desperately clinging to anything even faintly Antipodean, while Root has basically committed treason.
Regarding the confrontation, The Sydney Morning Herald says it featured a ‘glancing blow’ to Root’s chin. Sounds to us like Warner chinned Root and the wee man took it like a proper Yorkshireman.
Why did it happen? Well, that’s a matter for conjecture. Why not go on Twitter and read some hilarious jokes about bullying. Joe Root looks really young, you see.
Update: Apparently Root had been wearing a wig as a fake beard. Warner pulled it off before swinging, clearly believing that fake hair would entirely neuter his weedy blow. This may also shed light on the motive for the act: David Warner will not stand for inappropriate usage of a wig.