Tasers are not, "not lethal " . They are, "less lethal ".
Any time you are armed know that everytime less lethal instruments are used is not justification to use deadly force to engage the threat.

You need to take into consideration if backup officers can help, is there threats of death, can you create distance or a barrier to protect yourself. One thing is to use a vehicle to protect yourself when you first make contact.
Everybody went home safe, learn from it.