IMO, it sounds as if MR may be adding to/adjusting his timeline, after meeting with investigators & hearing their questions.
I am sure LE was told this information by MR shortly after reporting his son missing. I doubt this is a "new" disclosure. Since LE checked the house shortly after Dylan was reported missing, the bowl was probably still sitting by the sink.
If MR is telling the truth, then there is something very nefarious going on, and this only heightens the mystery. Nothing makes clear sense from what we know so far.