A quick thought...

So, while looking for bunk beds for my kids, I noticed how in many of the bunk beds the bolts and/or screws are countersunk yet the caps are exposed and detract from the look of the furniture. I am not the only one who has noticed this, as read on reviews of the said furniture. I instantly thought of.... Hey, I can print a removable cover. However, that was quickly dashed by the next ensuing thought..... Hey, if it is removable my youngest is sure to try to remove it and that could be a choking hazard if it was removed.  So, that kind of answered the question about exposed countersunk bolt and screw heads in kids furniture.

This lead me to another thought. Who is responsible for 3D printed design if it becomes hazardous for someone or something(a pet)? 

You can have number of parties involved or just a single person. I will look at the aspect where you have a maximum number of individuals interacting together.  A designer to create the design. A operator to print the design. A end-user that uses the printed part. However, the end-user may be more than one single person, it can be anyone that comes in contact with the physical design and may not use the design as intended. So, who is ultimately responsible if a printed part causes harm?  A very interesting conundrum that will surely be addressed in the courts in the coming decade.