Who are you planning to sue? DJI for not being able to help, or the government for stopping DJI from helping you? Maybe you should go for both to double your chances of success.
He's still making DJI ban videos, so maybe it's starting to sink in. Then again, he might just be chasing the latest hot topic for views. I guess we can't really blame him for that.
You should be able to get the date and time from the flight log file using DJI Assistant. However, all of the location data is encrypted, so you won't be able to extract any of that data.