EE & co-worker were tasked w/applying herbicide to plants & were using ATVs to access the site. EE became stuck. EE walked up to co-worker's ATV & tried to play out the winch line. After finding it wouldn't play out EE placed middle finger of lt hand in winch line hook & asked co-worker to run winch out. They didn't use remote winch controller & EE didn't use safety pull strap.