That has no pedals, so it’s entirely electric, not electric assist. Bike lanes in my area allow electric assist bicycles, but not electric-only motorbikes. To be considered a bicycle in my area, it:
cannot assist past 20mph (~32kmh) or 28mph (~45kmh) if there is a speedometer equipped
must be propelled by human power (hands or feet)
cannot be classified as a scooter or similar
Emotorbikes are just motorcycles with a battery instead of a gas tank, and thus are not allowed in the bike lane. So that person is probably operating their motorcycle illegally. It doesn’t matter what speed they’re going, it’s not allowed in the bike lane unless it’s propelled by human power.
If it happens again, I’d report it to the police. Keep doing that until they get some enforcement.