A few thoughts that crossed my mind:
- what if this was a 'childish' prank perpetrated by people too young to consider the consequences;
- what if someone actually intended to wipe out *all* the adults, for some reason E got lucky and failed to ingest her portion of the poison and she's just as much a target as the others?
- until toxicology comes back and we have more published facts, we don't actually know for sure that the group really did eat Beef Wellington with mushrooms - apparently this is only a 'leaked rumour' from a source close to the families;
- even if the group were poisoned with deadly nightcap mushrooms, that poison could have been in anything they ate, not just the mushrooms, if they were dried and powdered, it could have been in their coffee or suchlike;
- if the group of four adults travelled to E's house to share a meal, what if they stopped met up or stopped off for a coffee en route and in fact were all four poisoned in a different location by someone else entirely?
- likewise vice versa what if they travelled home together and stopped off for a drink or a coffee and were poisoned in that location?
- it is stated in the MSM that E claims to have purchased the mushrooms she did use for the meal in a carton from a store, ie they were not hand picked by herself. What if that carton had been tampered with or simply had the wrong sort of mushroom in it by mistake?