Thanks for feedback. They're not as much mistakes as not expecting players to be really mean to Sarah while trying to romance Annie.
![Wink ;) ;)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
I'll add notes mentioning these two events won't occur if the player has poor relationship with Sarah.
Do not worry though, neither of these two events are particularly important in regards to Annie, so if you don't like Sarah it's not a problem not to get them.
A word of caution though: these two girls are friends and they talk to each other, so doing bad things to one could lead to difficulties with the other.