Our opspecs requiring quick turn arounds only required flow checks on oxygen on initial flights on first flight of the day. We flew the whole day with no crew oxygen and didn't know it. The pressure was right but the bottle was turned off. If we had depressurized we would have had no oxygen. I don't know what their opspecs were but putting people in jail is not right. Mistakes were made but they put the wrong people in jail. Hopefully they will rectify this. It is embarassing to think Greece can not understand this.