The bolts holding the front plate of the stem to the stem body can be pulled out of the threads while the bike is being ridden, causing the rider to lose control of the bike and fall.
The latch pin can disengage from the latch allowing the door to open while the vehicle is moving. This can pose a risk of ejection of an unrestrained rider and impact or laceration hazards.
The front wheel can come loose during use and cause the stroller to tip over, posing a fall and injury hazard to children in the stroller and adults pushing the stroller.