M.R.
If you have not recorded new videos since he deleted them, they should still be there. I would contact geek squad (at best buy) or do a search in your area for someone that specializes in computer repair. My friend had lost 200 pictures from our trip to Hawaii and found a computer professional to help her restore them all! I'm sure there might be some software online, but I wouldn't take the chance trying to do it myself I were in your shoes in case there is a chance of deleting them entirely. Good luck!