In Plato's allegory the epistemological background is clear. The person seeing the ideas and not only their shadowy representations knew to know better.

But in RL life is a bit more complicated. As was already pointed out, we can't know if a person differing is nearer or fartehr from reality than we are. (Provided and accepted for the moment that there is ONE reality...) Plato did see and explain a lot of things and is still accepted in parts, but in other parts his findings are not accepted anymore.

Was he nearer to the shadow, or nearer to light, or (my personal opinion) both?

This comment does not infer that we can't say or know anything. It is not meant as an attack But I want to set US (or preferably ME?) into the allegory and look for the right place.