Who calls the ambulance on Angelique's suicide attempt? Loïc doesn't realize anything's wrong until he hears the ambulance and the medics have already removed Angelique from her house. Their homes seem pretty isolated, so it's not like there'd be anybody else around to catch it. What's more, she doesn't even turn the lights on during her attempt, so there's no reason for an outside person to think anyone's home, let alone in danger. We see Angelique's eyes close as her heart stops, so there's no possibility she got cold feet and called in to the hospital herself. By this point she's alienated her friends and her house is one big Room Fullof Crazy, so nobody she knew would have popped over... so how did anybody know she was in trouble???
Maybe Angelique called the ambulance beforehand? Fake attempted suicide is a Yandere tactic after all.
Or maybe one of the other neighbors smelled the gas.