They're not treating it like a bicycle, are they? Some folkes with really high bike seats will have to lean when they stop to put a foot down, may not even be realizing it.
Bit different with 650# motosickle
Then there's the "don't stop while turning" rule.
Otherwise, as has been said, eyes up, etc. Motorcyclists cannot watch their own bike while riding it. Not even in the windows they ride by. Bad things happen.
I'd be willing to bet that it's a lady, and that she's looking down to see where to put her feet.
And to see where the bike is when it's stopped.
Guys generally have a "charge ahead" attitude, but ladies have gotten used to picking up the kid's toys and the dirty socks. And tripping and falling hurt. So they look down.
I'd also bet they're having problems with turns and high speeds.
Some people just can't figure out that by the time they look down to see where they are, they've already gone past where they were.
Oh, one more thing... if they're not using the front and rear brakes together... just or mostly the rear, the bike won't stop where they think it should, they'll panic and grab the front, and by default, tweak the front wheel a bit... and go down.
LOOK UP. repeat. forever.
It's actually hard for some people to do. One thing to check is to ride while they drive a cage. I used to ask my driver's ed students how many vehicles were ahead of them. Got some interesting answers, but it made a point.
Look up, chin up. Not just eyes up... you can keep you head down and think your eyes are up. Not even close. Chin up works better.
Hope something someone suggested helps.
mary