I did point out on the first page of this thread that Calpol does not have antihistamine, which is clamed by Sr Amaral in the video. He has obviously got confused as to what the medicine does, does not do.
He is implying that this may have been used to drug the children to make them sleep. It is highly unlikely that this would be used for such a scenario. It may well help children to sleep if they are in pain from teething/earache etc. However it is known that Calpol contains paracetamol and people can accidentally overdose. The children would have had to have been given a huge amount to knock them out! As a theory I would dismiss this instantly. The fact that Kate wanted the children's hair to be checked- it is well known in the medical profession that the hair follicles of drug users can highlight certain drugs for up to a year!
If a deliberate drugging theory is to be considered by who ever is suspected of administering the drug. Calpol would not be the chosen drug to do this.
Another theory in the equation is accidental drugging- child wakes up- see prescription tablets and thinking they are sweets eats some.
Please note I am not stating anything typed in this post to have happened, these are just theories I have come across over the years and worthy of a mention even just to be dismissed, or debated.