They should have been permitted to wear them but I would have questioned a child wearing a mask as UK guidance doesn't recommend it.
The article is misleadingly selective about the oxygen thing as the British Standards Institute does stipulate a maximum permissible CO2 concentration within...
The point still stands, that their outcome has been nothing extraordinary set against the last 20 years.
Furthermore, they consider their main error to have been care home management rather than absent lockdowns.
'comparable country' = 'cherry-picked country' - and even if we grant that line of argument, their death rate is still better than pretty much every Swedish year before 2010, which is a far, far better outcome than the flawed modelling predicted.