In any situation, deadly force is either authorized by the situation, or not. If not, then there is no reason (aside from sadism or psychopathy) to use a taser.
Nets, adhesive spray, can be used as less lethal tools. Tasers, not so much.
I'll try to remember that next time I'm fighting with a crack head I just chased into an alley from a stolen car and my back-up unit is five minutes away still. Thanks for setting it straight