The Washington Post claims that the Egyptian and Russian regimes are far less adept at fighting terrorism than they are at lying.
Source: Russian and Egyptian officials are not to be trusted over airline crash – The Washington Post
This article claims that the Egyptian and Russian leaders want to avoid being accused of being indirectly responsible for the air crash. Egypt is responsible for security at the airport. Russia’s intervention in Syria has drawn retaliation.
US opinion now supports the UK that this was a terrorist attack, probably a bomb planted at the airport.