There you go. You've answered your own question. The WLM may(?!) have racist undertones and that's why he lost his job. He wouldn't have flown that banner had the BLM taken place would he? Because there's no need - white lives have always mattered.
BLM had some theft and some violence, vast majority of people were peaceful and wanting to get their voices heard. I don't think it's that common to have such a big protest 100% peaceful, there's always a small percentage of tossers want to fight. Same as when the more right wing members protested back recently - there were a few who attacked the police. Used to be a rentamob for football matches etc.