I don't know what state you were trained in, and it might be a good personal policy to retreat when possible, but most states do not have a legal obligation to retreat from a deadly threat. Most states are Stand Your Ground states.
Even in those that aren't, the duty to retreat applied only as long as it can be done in safety.
Even in those that aren't, the duty to retreat applied only as long as it can be done in safety.
Nice in theory, but in practice, you'll get tangled up with the Money & Time-Sucking Kraken that is the Great Big Giant Large Crimnel Jesters Machine. Retreat to safety, I say.