Ofcourse, if it was a compulsion , she wouldn't have betrayed them and Tyler.
Have you seen all episodes Jules was in? She explains loyalty and relationship shared between werewolves. Even Mason was looking out for Tyler. Jules took tyler in their pack and wanted to help him control werewolf side. But Hayley was setting up hybrids(originally werewolves) voluntarily and betraying them.
Loyalty can be forced through sire bond. But a werewolf betraying their own voluntarily is like a carnivore going vegan.
I did but that was when they aired so my memories are rusty.
I just assumed it wasnt as binding as you swear it is. Im guessing the writers forgot or ignored or didnt mean it to be that binding either.