I will check the pages to see if this was mentioned or not, but for now here it is.
I decided to try and track more hidden "events" that may pop up.
So, on my first visit to Novigard I went to the houses outside, near the shop of Eilal (I hope I spelled his name right). Anyway, few witch hunters were knocking at the door and screaming for a man to come out and I decided to wait and followed in.
An event was triggered in which they blamed him for aiding the lodge in the previous game event.
You have an option to either say something or not. If you do, you will fight witch-hunters in high "skull" difficulty, since it is considered as to fight a guard in a city I think? The mage they hunt (with his family) help you during the battle. Afterward he gives you a rune item.
Another "event", which for some reason I can't active anymore, happened to me when I first played the witcher (before the expensions and DLC come about). When entering the city of the red baron, a man urges his young girl to flee before the baron will see her and take her, and the girl leaves the house.
I don't know why it never happened anymore, but I clearly remember it happened on my very first playthrough and I saw articles mentioning this event as well.
If I find more things I'll post them here.