In Oregon the biker probably ran the stopsign too.
In Oregon it's legal for a bicyclist to run a stop sign, provided there's no conflicting traffic.
Oregon law allows cyclists to treat a stop sign like a yield sign and a stop light like a stop sign. So there is no strict requirement for a cyclist to stop at a stop sign.
When they enacted that law, the incidence of bicyclists being struck by cagers (motorists) while negotiating an intersection dropped by 18%.