Sending a lie comes from the author of the lie. That someone accepts the lie does not alter responsibility. Just as we are told that God hardened the heart of the Pharaoh...who presumably would have let the Israelite's go had his heart not been hardened by God. We are not told that God enlightened the deceived, but sent a lying spirit in order to deceive.
Judges 9:23And God sent an evil spirit between Abimelech and the leaders of Shechem, and the leaders of Shechem dealt treacherously with Abimelech,
Ezekiel 14:9And if the prophet is deceived and speaks a word, I, the LORD, have deceived that prophet, and I will stretch out my hand against him and will destroy him from the midst of my people Israel.
2 Thessalonians 2:11Therefore God sends them a strong delusion, so that they may believe what is false,