Unless you can explain why West didn't tell Jeremy his father had just called, the whole thing falls flat. Your informant argument doesn't work Mike. John, who is an ex cop is saying the same thing and he would know. Jeremy wasn't an informant, he would be a concerned citizen and worried about his dad. However, in the end game, West would have known Jeremy was innocent and so would the others - to suggest they framed an innocent man - when they had the perfect suspect - is ridiculous.
First of all, any person providing information to the police, is regarded as an ' informant', whether it be by telephone, in writing, or in person face to face. OK, I will humour you, 'a witness'. Cops don't tell witnesses, what other witnesses have told them', its unethical for obvious reasons...