
Do you think the one who made the letter is not the Uncle but rather someone? Seeing that everyone agreed that's little A's Uncle, he looked shocked that his Nephew is on the farm?
Also, having a Theory, maybe little A found the experiment files that he was supposed to get, like him being experimented on, and someone found out, and the Uncle took the blame instead, making it the reason why the Uncle has animal features...?
I bet his friend is the one who wrote the novel.
good twist