I could be wrong but did Todd impulsively agree after a fight with Billy to better himself
I agree Michael died of a heart attack brought on by his snooping in the site office over knowing Phelan was doing wrong
Michael was very loud about his suspicions as was Anna too so I am hoping others besides Andy and Gary too will start to question Michael's death at the site and directly then Phelan
Did Billy also question Todd's change on Phelan?