It's still a dilemna for him as the guy's property is being illegaly damaged by his tenants while he is expected to take legal action against them! I can see his dilemna exactly.
This is why IMO the PRTB process is broken. Its just too slow. Can't see it getting any more resources to speed it up either.
Last time I had tenant like that I gave them back their deposit to get rid of them. Despite because of damage they had caused the propery we were entitled to keep it. It wouldn't have covered the cost anyway.