Trying to help out a friend here:
Original routing PHX-ORD-ZRH-CDG (ORD-ZRH-CDG on Swiss). PHX-ORD gets delayed they get re-routed ORD-FRA-CDG on LH. They show up in Paris and bags nowhere to be found. They report them lost at the Star Alliance missing bag office in CDG (told bags are still in ORD), eventually they receive them 5 days later when they are in Munich (they hopped around a lot due to their honeymoon). The bag on its arrival is severely damaged and unusable. They have pictures with timestamps, case ID etc... What airline do they go to for compensation, and what is the best course of action for them to file a claim?