I would be concerned that not only does he not know anything about beer but that he knows nothing about running a restaurant and nothing about running a business in general.
That was my first thought.
Mine too! There are certainly a lot of things that can go wrong with this....very wrong! Actually, when he told me that he would allow me 50% ownership, that raised a red flag. If it were my business, I would want to own 100% and simply hire the people to handle the areas I don't know (i.e. food prep, management, brewing, etc...), so I'm kinda curious as to why he would want me to own 50%. Maybe he just wants to make sure I stay - again, kinda weird since he doesn't know me. I'm sure I'll find out in due time...but I'm not making any commitments until I'm sure of it.
On the liability front, I have been under the impression that an LLC will offer at least some protection to your personal assets? At any rate, I'm not going to borrow any money for this venture, so I'll be sure to think twice before taking any offers of ownership.