He is "likely" BS-ing? If you did not do what he says you did, then there is no way he could have you on video and you should be free and clear and KNOW that the detective has no evidence against you.
So, what you are saying is that the detective is correct? That they have you on tape (or COULD have you on tape)?
If that is the case, then you need to keep quiet because you face at least two felonies and possibly more.