thats why it was written so chelsea didnt go in. Lucas is shocked as he was expecting denise but it isnt, he says it is just so they all still think denise killed owen and killed herself. Denise is really at her sisters and turns up shortly after her funeral.
nut when he saw the body he was not shocked it was not denise. If it was not her would he have not reacted diff and been more worried as to where the hell she was?