Ouch! This thing is very unforgiving of any mistake, 20mm dry branch or 30mm live wood and it's cut in the blink of an eye - and the trigger pull is light. I;ve seen it recommended to keep the other hand in your pocket but that sounds a bit impractical. Maybe a steel mesh glove would help with the digit being a bit mashed instead of severed but in the end safety is in your own head. I've worked with 'dangerous' tools all my life and haven't lost any important bits yet (touch wood... lol).
IMHO it could do with a handle across the top purely for putting your other hand on, or maybe even for a safety switch like on a hedge trimmer.