First of all , he was an EMT (Emergency Medical Technician). An EMT is someone who helps and is trained to provide emergency medical care at the scene of an accident or in an ambulance. Of course, this looked bad for Adnan because this proves that he would have been able to strangle Hae or kill her easily with his techniques. But again, that does not prove anything. This does not prove he had the balls to Kill someone when his job was to help others. Another piece of evidence would be when Jay and Adnan were at Kathy’s house. Kathy says in ( episode 9) that they both seem a bit suspicious, but remembered that they were smoking weed. Weed at some point makes you panic and overreact to certain things, even the smallest move. According to Leaf Science, Marijuana side effects could be paranoia , anxiety and memory impairment which means someone under this influences can have difficulties remembering things and overreact. Adding up to this same situation, Kathy also says Adnan received a call that made him say things like “What am I supposed to say ?” or “What should I do?“. Humans react in a very strange way, more if you are under pressure or being scared. Keep in mind that they are high, everything is crazy to them at this