I find the hand eating worrysome because it wasn't always like that.
Can you be more precise about what you think, please ? For me, this behavior is one great enigma. I have an explanation of my own. But I rather ear yours before (if any), just not to influence.
I don't have any clear picture but in my family it's quite normal for young boys to eat with their hands. No one likes it, but it's mostly ignored. We all start out 'rather floppy' in terms of coordination and strength, and catch up in our 20s.
No sports stars in our high school years.
None of those kids started with a fork and went to hands, though. It's sort of 'assumed' that these boys just aren't coordinated or patient enough to use a fork until they 'grow into themselves.' Eventually the children grow up and start to care about how their peers percieve them and start using a fork - at the older age they are more motivated and more coordinated as well so it isn't as much work.
At our house we use the expression, 'is this the hill you want to die on?' when judging which of the child's behavior needs to be corrected. Things like kindness to others, being on time, and love of learning seemed so all consuming that I dodged the question of manners. If I had been using the 'Transforming the difficult child workbook' back then I would have known how to give a correction without all the effort and heartache (maybe) and things might have been different. We will never know.
I myself hold the fork in the right hand and the knife in the left hand, which I understand is normal in Europe, but I've gotten plenty of negative comments about this in the U.S. Here my understanding is that folks pick up the knife with their right hand to cut, and then rest it on the plate, and then pick up the fork with the right hand and so forth back and forth. This seems way to complicated to me, but the fact that I didn't 'naturally' notice what others do and immitate them shows some mild motor planning issues/attention issues. Frankly, while I'm eating I want to relax and not worry about a dirty knife sliding off the plate and one the table cloth.
All of this fall under the general catagory of what my son calls: 'What is easy for me is hard for others, and what is hard for me is easy for other kids.' I'm glad that he is getting the idea early that giftedness doesn't equal perfection in all areas. It took me rather longer to get that message.
We also have a French family who are family friends, and my husband warned us that table manners are a much more deeply held value for them than for us. This may not be true for your family, but if it is, and your son used to be able to use the fork with some automaticity, the fact that he isn't now may point to the idea that his overall 'capasity' to do difficult things is low right now. I'd also want a medical doctor to make sure there isn't a disease interfering with his strength or coordination.
Peace and Smiles,
Grinity
