“In general, to obtain a full effect: both darts must hit the target, the copper wires must remain attached and useable, and heavy clothes, if not completely penetrated, must be near the subject's body. When these conditions are not met, the expected results may not be obtained, and a Taser officer may need to reapply the device either with a new cartridge or in the stun mode. “
http://www.pointshooting.com/1ataserd.htm
I believe the LEO on the left was close to being outside of the recommended range for use against heavy clothing - if indeed he was firing a Taser(facts not in evidence)
At full arm extension, he got within 12 feet, or maybe a foot less than that.
You can see him messing with the wires from the Taser after he gets around the bush.