While Bosman and Huber's (the others have their moments but those two especially) spoilerphobia and media blackouts can be cute now and then, I could see them getting really precious about it.
They've got a limited number of people trying to cover as much as possible, in order to help EZA attract a wider audience and grow. The more people duck out of that, the greater the burden on the rest, and given that Brandon was already feeling the strain of his workload prior to E3 I can understand if he gets frustrated.