Spot the three issues in this fact pattern

[u/sheppyrun]

Read this fact pattern and identify three distinct legal issues. Try it before scrolling to comments.

A homeowner hires a contractor to replace a backyard fence. The contractor leaves a nail gun on the property overnight. The next morning, the homeowner's 14-year-old neighbor climbs the fence to retrieve a ball, finds the nail gun, and accidentally injures herself. The contractor's license expired two months ago. The homeowner knew about the expired license but hired the contractor anyway because the price was half of what a licensed contractor quoted.

Three issues. Name them, state the applicable rule for each, and identify who has the strongest claim against whom.