My first thought on this case is that we really don't know what the state of her house was other than "unusual." The dishes could literally be whatever she ate dinner on, and by the bed a mug of tea that went moldy. The cats vomiting seems normal if they were left alone for days, especially if they were stressed. The door was open, so they could have been sampling any number of edibles outside they weren't used to. Cats also just vomit hairballs on a regular basis so that detail, to me, is just further indication that she had not returned and had been gone awhile.
The delay to report is worrying. Is there not a neighbour or mailman or LE patrol that could have noticed her door wide open?
The phone's path makes me think dumping evidence. But if this is foul play, whoever left her house in such a state is disorganised so it makes sense they wouldn't check her for the phone or not realize it was just in sleep mode. But then its most likely they killed her in the house and wouldn't there be substantial evidence in that case? If it was left on by a killer to divert attention, why leave the house in that state? I wonder if the door was left open because whoever left it that way actually had some empathy for the cats being left there and wanted to give them an escape. This would mean that person knew Erica wasn't coming back whether it was her or someone else.
