You did the right thing.
Normally, I could care less about neglectful parents and how they mis-manage their kids (poor diet, lousy middos, ect) but bike riding has a special place in my heart.
The only thing I would have added to the 1st mother is that I’m going to call Child Services and report the fact that the kid is riding unsupervised, and without a helmet.
THAT gets their undivided attention. Not becuase they care about the kids.. but becuase it might affect their benefits.