Hayek's True and Earlier Views on Keynes
27 June 2017 | Pago Pago, American Samoa
And as Charles Park adds, "Hayek also said in Road to Serfdom that government could regulate industries... In this he seems to indicate he is ware of negative externalities and market failure." Hayek just later turned to propagandizing contrary views which he found were personally more rewarding and also more consistent with the Austrian school for which he was an emerging leader.
This also explains why Keynes liked the book Road to Serfdom.