Based on the information from various sources, there are different theories about which animatronic killed Phone Guy in the game "Five Nights at Freddys 1." Some sources suggest that Golden Freddy is the one who killed Phone Guy, while others argue that it was Chica. The evidence supporting Golden Freddy includes the unique scream that is played when Golden Freddy is in the office after the Kill Screen appears, which is heard in the call before Phone Guys death. On the other hand, some fans believe that Chica was responsible, as her moaning can be heard in the call, and the left door was closed, ruling out other suspects.
The debate about who killed Phone Guy continues among fans, and there are various interpretations of the evidence from the game. Ultimately, the true identity of the animatronic responsible for Phone Guys demise remains a subject of speculation and interpretation within the "Five Nights at Freddys" community.