What you're saying is more or less exactly what the paper was getting at. It's hard to say based on a short Internet comment, but it sounds like the spot where

What you're saying is more or less exactly what the paper was getting at. It's hard to say based on a short Internet comment, but it sounds like the spot where your disagreement comes from is that you're understanding the word "justified" in a slightly different way from how epistemologists were using it. For example, one of the responses to Gettier's paper was to suggest that maybe the definition of "justified" should be altered to include a provision that invalidating the justification would imply that the belief is false. So, for example, under that modified definition, the visual evidence couldn't serve as a justification of the belief that there is a cow in the field, because it allows the possibility that it isn't a cow but there still is one in the field. On the other hand, it would work for justifying a belief like, "I can see a cow from here." (Yeah, there's another cow in the field, but it's not the one you think you see.) But, still, that wasn't quite the definition that the mid-century epistemologists who made up Gettier's audience were using. (ETA: Also, the original paper didn't involve cattle at all. Wikipedia has what looks like a good summary: https://en.wikipedia.org/wiki/Gettier_problem#Gettier's_two_original_counterexamples https://en.wikipedia.org/wiki/Gettier_problem#Gettier's_two_...)