Reminder: BLM protests had wide-scale looting. Looters breaking into luxury stores and hauling off with anything not bolted down. Not the same scope. Not the same standard.
In Bellevue, the police did neither, and instead, talked with the protesters, and there was no looting anywhere near the protest areas.
If you actually cared about minimizing looting, you should probably not attack peaceful protestors on public streets. The chaos that starts is what gives looters cover to operate.
Also as you imply, why would being treated poorly by a public servant (the police) justify the looting of an unrelated private party? It doesn’t. One is not a justified cause for the other.