Through a process of elimination, Gary determined that Olivia had to be the one who turned Marie into a Werewolf. This conclusion was reached as Kai's reaction indicated he was not responsible, and Midwak was also ruled out. Given Olivia's past actions, including her use of the whip to save the group, Gary could not imagine her acting with harmful intentions.
In the end, Marie was safe, and Gary had to address the new reality he was facing.
‘Now that she is a Werewolf, there is a good chance that she won’t just be involved in gang matters, and that Midwak’s old Pack might go after in the future. In that case, the best thing to do is to allow her to evolve, and assign her a Class.’
Having gone through the process himself in the past, Gary knew that the process of receiving a Class was quite painful. Remembering Kai’s transformation, and Olivia’s complaint about no prior notice, he decided to warn Marie in advance by sending her a text.