There's more to bullying than shouting and yelling and blowing off at people. Starting rumours, blaming/picking on other people for your own mistakes, the digs disguised as jokes unless you're on the receiving end, the complete blanking out of an individual ... there are so many ways to be a bully without ranting and raving.
Brown's supporters may deny he's a bully (well, they would - they get too many back-handers not to), and he may deny it himself (most of them do), but my guess is they're all only addressing the shouting and yelling part of it.