Would really depend on the circumstances (which I also couldn't find much info about).
From what I can find, the 60 day ban was unanimously extended another 60 days (till mid June):
For those who may have missed the news, Key Biscayne residents can store their nifty e-bikes and electric scooters until mid-June after the Village Council voted 7-0 during their last
www.islandernews.com
Since helmet wearing is generally not a legal requirement for an adult riding a bike, probably wouldn't be a defense. I continue to find the focus on the victims lack of helmet quite gross. Its the same crap the media pulls when an idiot motorist on a cell phone/speeding/whatever kills a cyclist. Merits of helmet-wearing aside, people should be able to ride around and not get run over by idiots, and when it happens I'm perfectly comfortable placing 100% of the blame on the idiot instead of the person who was hit.
Laws often are written to the lowest common denominator. Which is why its important to call out yahoos and idiots and not cover for them.