As to the definition they are agreeing on, from the NHTSA website [1]:

“Initiated safety recalls require a manufacturer's action to announce and remedy the defects.

A recall is issued when a manufacturer or NHTSA determines that a vehicle, equipment, car seat, or tire creates an unreasonable safety risk or fails to meet minimum safety standards.”

Creating a unreasonable safety risk or failing to meet minimum safety standards is kind of the definition of dangerous. And there is a defect causing it. So, yes, Tesla claims it is a “dangerous defect” and I think Tesla knows more about their products being dangerous than you do.

[1] https://www.nhtsa.gov/recalls