Which part of "safe and effective" am I missing?

Taser International has described their tasers as "...safe and effective..."

There's a bit of a debate about the safe part. Maybe you've heard...

Now, what about the effective part?

Houston Chronicle (17 May 2010) - ...Officer E. Garza shocked Jeffrey Marlon Peterson, 37, with a taser, but it appeared to have no affect. A second officer, D. Alexander, who arrived after the traffic stop, also used her taser on Peterson, but he again appeared unaffected. ...Peterson ran to his pickup and got a handgun, which he pointed at Garza. ... [LINK]

So the first taser has no affect.

The second taser also has no affect.

How is the claim that tasers are "effective" holding up?

The end result is that the police are left staring down the barrel of a real gun.

Both officers told Peterson to drop the gun, but he refused... Garza fired at least once, hitting him. Peterson ... is in critical condition, but is expected to survive. He is charged with aggravated assault against a public servant. The officers at the scene were not injured.

Thank God. No thanks to The Church of Taser.

Draw your own conclusions about their marketing claims...