After giving my husband oral with no sore, 12 hrs later i had a cold sore symptoms and a couple hours later a sore how likely is it he could get it?

Probably not, but.: The virus sheds from an open sore usually. But there can be shedding of the virus without symptoms at any time. This is not likely but not impossible either. However, almost everybody has the herpes simplex-1 virus (HSV-1) in them and hardly anybody gets HSV-1 transmission to the genitals, so don't worry about it too much. There are no guarantees in the world (except death and taxes).

He could, : It's possible. You were shedding the virus before you broke out. We used say that mouth ulcers were herpes simplex 1 and genital sores a were herpes simplex 2 but with oral sex becoming "standard" it is possible to have either type in both locations.