Thanks for the feedback.
The neighbour turns randomly, with a reaction cooldown of 0.5 seconds, which means, if you started digging 0.5 seconds after he turned or less, he won't notice you. The time your brain needs, to notice that the neighbour turned is 0.2 seconds which means you have 0.3 seconds to react.
I don't know what's about the lag, the whole snow and scoring system was mickkay’s part, he will have to respond to your question.
Edit: Maybe you think the slow movement is lag, it’s just that the player moves slower when in high snow. Otherwise i don’t know how to fix it.