Even if I grant that the in game morality should work the same as real world morality, that doesn't mean that the knowledge and capabilities and physical repercussions in the game world work the same as the real world (see, for example, the thread on falling damage).
Maybe the heavily armored dwarf has tried sprinting after people before and is virtually certain they'll lose the race? Do you randomly add values to the speed of players you DM when they're running to simulate them never being sure how fast they are, or are the characters all just oblivious to how running has always worked for them in that world?
How much game talk goes on at tables seems like a by the table thing. I'm fairly certain one-true-waying is not LG.
But ok -- even if it was just the Dwarf being 100% certain they couldn't catch the child and the Dwarf being 100% certain the child wouldn't be injured... doesn't that just make it a question of the Dwarf's judgement and/or sanity and not of their alignment?
Is the real issue the lack of verisimilitude or with the player giving the character game mechanic knowledge, and not with the morality?
The character cant possibly know that!
Maybe the heavily armored dwarf has tried sprinting after people before and is virtually certain they'll lose the race? Do you randomly add values to the speed of players you DM when they're running to simulate them never being sure how fast they are, or are the characters all just oblivious to how running has always worked for them in that world?
Drop the game talk.
How much game talk goes on at tables seems like a by the table thing. I'm fairly certain one-true-waying is not LG.

But ok -- even if it was just the Dwarf being 100% certain they couldn't catch the child and the Dwarf being 100% certain the child wouldn't be injured... doesn't that just make it a question of the Dwarf's judgement and/or sanity and not of their alignment?
Is the real issue the lack of verisimilitude or with the player giving the character game mechanic knowledge, and not with the morality?