If the case is that daily total ratio is not enough,and a single meals ratio can also have an effect, then you maybe rightHe stated that he was taking gelatin as a supplement before bed (on an otherwise empty stomach?). A large enough bolus of manufactured gelatin could create an environment overnight favorable to the creation of a cold sore overnight.
Heretofore, I thought that the the daily ratio of lysine to arginine would protect against cold sores. I now believe that a cold sore could in fact materialize after a single bolus of manufactured gelatin at the end of the day followed by the normal nightly fast.
The lysine to arginine ratio is well known in the cold sore community. His daily ratio may not be as high as he thought. There are large number of foods that he might have been eating that had too much arginine.