It won't work. You would need to back up your claim with proof that someone hacked your router. You can't drive a car that is easily breakable and expect the court to clear you of any responsibility if it causes harm because it broke while you were driving.
But if it’s the isp delivered router they should carry the responsibility
An allegory here would be someone stealing an easily stealable car (e.g. doing the Kia Challenge) and causing damage or injury. The thief would be liable, not the owner