Every electric leaf blower I've seen has a double insulated motor and the housing and blower tube are plastic. Even the heavy duty gasoline back-pack mounted units I've seen have plastic blower tubes. I wish the story had provided a few more details.
Sounds like it was a bonding problem? All metal must be bonded on swimming pools, because you can be shocked even with proper grounding. Being short of details, who knows what condition his blower was in? I dont think the lawyers will ask?
Was working on an outside unit this morning was kneeling on cond. unit went to open service disconnect and pow knocked me on my butt. I had shut lever down but the insulation on line side was chard and fell off when I opened cover and top of lid touched a wire the fire flew, that was my eye opener this morning.