Electra shows Clytemnestra a knife and then presents her own hair as if she has hacked it off. When she turns, her hair has been professionally and neatly trimmed very short.
Towards the end of the film, when Elektra is speaking hateful words over the corpse of Aegisthus, who has been killed by Orestes, you can clearly see the pulse in Aegisthus's neck.
Having seconds thought about killing Klytaemnistra, Orestis proclaims a devil, not a god, must have spoken to the oracle who told him to seek vengeance. As it happens, the word "devil" comes from the Greek word diábolos which means slanderer or accuser, not the Christian or Islamic word for a supernatural enemy of humankind tempting people to commit evil deeds.