I’d say inconsiderate is more like ignoring a request to be considerate. Accidental inconsideration is normal and happens to everyon, especially neurodivergent people.

Infamous?

Have you considered that he just forgot? People can not be fully attentive sometimes. He basically said thanks for reminding me and sorry about that. That’s ok in my book

Its a basic physics thing. You see not more of your body when you take a step back. That is normal and expected.

Nitpick: you misunderstood half life. 10h is 25%