Over the past couple of days, I've been thinking about this idea that EP was really intelligent, and how this has been used to defend the idea that she wouldn't have planned something so badly. Regardless of whether people think she is innocent or guilty, almost all essentially agree that Erin acted out of panic in the days following the lunch.
Innocent - Erin's ill-thought out actions were done in a panic and a result of trying to cover up her culpability for their deaths.
Guilty - Erin's ill-thought out actions were done in a panic as a result of not suspecting they would identify the Death Caps and therefore not expecting she would be caught.
Whilst there was clearly some degree of panic, I'm going to argue that rather than being a panicked response, many of EP's actions were maybe a reflection that she wasn't as thorough or dare I say clever as people think she was.
Take the most obvious example: the disposing of the dehydrator at the tip. Obviously, this was a very stressful time but it wasn't a decision made in absolute panic. She spent the previous day presumably sitting around in hospital and obviously realised at this point that she needed to cover her tracks. However, despite this her plan for covering up was really poor. She forgot that she still had the manual and didn't seem to consider that it would be obviously traceable from the tip. Even if she was innocent, this is a real rookie mistake to make. There were much better ways of getting rid of it even in a panic.
Then you have the search at the house, and the police interview. These happened almost a week after the meal. Again, regardless of guilt this must have been stressful, but this is a long time to consider how she could best get herself out of the mess that she was in. The result was an utter mess: she decided literally at the last minute to get rid of her main phone. She factory reset one of her phones multiple times. You'd think she would have been aware of how incriminating this would look and how easy it would have been to identify and have thought of a better solution.
She also had adequate time to get her story straight before the second interview. The most obvious way to make her situation better would have been to admit to foraging very early on. You could argue that the Woolworths and Asian grocer story was a panicked answer at her first police interview, but she sat there for a whole week and decided to stick with it clearly thinking it was her best bet. In reality, it was a terrible answer at that time and one that again massively incriminated her when she didn't admit to foraging until 2 years later.
Maybe she wasn't as clever as everybody thinks, or at the very least clever in a different non-common sensical way.