> To use a dog metaphor, a chainsaw tends to growl before it bites.

I believe the author is mistaken about why chainsaws don't cause more harm than they do. There are multiple of ways in which a chainsaw will kill or destroy, without any warning. Kickback is very quick. A tree falling in the wrong direction comes without warning.

Personally, I suspect there are 2 main reasons why chainsaws don't cause more harm.

A) They've been around for 100 years, and they've been causing fatalities and injuries for 100 years. People have invented ways to reduce the risk. Any chain you can readily buy is a low-kickback chain, and the saw comes with a chain brake. It doesn't completely remove the risk, but it substantially reduces it.

B) They've been around for 100 years, and they've been causing fatalities and injuries for 100 years. People are aware that chainsaws are inherently dangerous. Even someone without any training, and without looking at the safety instructions, understands that one of these will take off a limb without blinking.

What this means for the rest of the metaphor, I'm not sure.

>>chainsaw tends to growl before it bites.

It doesn't tend to; it growls continuously : treat me wrong an i will eat you.