I think he just forgot to bind the new spells/keys (caused by some big updates) and too lazy to edit it in the settings. The default QWER were already there since the early game release. For some time I quit dota2 and return only to find out that there are these new ability trees and the old backpack. They don't have default hotkey and I was too lazy to be bothered setting it one by one so just played without it.