The UK situation was a bit different, as that was the state detaining people for several days and looking into criminal charges.
In civil court, anyone can bring a lawsuit alleging a wrong, but that doesn't mean it will go anywhere. I could bring a lawsuit tomorrow against the Weather Channel, alleging they caused me pain and suffering from all the strong winds that were whipping the clays all over the place today. Totally bunk, but I could still file it, and it would then get tossed out with a pre-trial motion to dismiss. I suspect this one will get tossed in pretrial proceedings too. If it's completely frivolous, there are sanctions and other penalties the court can impose.
Personally, I couldn't help but think what a weird fact scenario this is. He broke in, put a gun to his head, tied him up, "rummaged his room for valuables", then granted him permission to go use the bathroom (

). Do burglar's recognize the hall pass these days? "Excuse me, sir that just had a gun to my head, but I really need to use the ittle boy's room. May I be excused?" Maybe I missed that memo.
So, the 90 year old then shot the 30 year old in the jaw (with one of the 5 guns he keeps in the john

), out-wrestled him, and chased him off... sorry, but something doesn't add up here. Personally, I don't think we have an accurate depiction of what went on here, and I would be cautious about jumping to conclusions based on these alleged facts. Keep in mind, that news article is written based on one person's version of the story, but that doesn't mean it's actually what happened.