The fact he said (last year) that he believed there is a higher power, proves he is not an atheist, regardless of him saying last week he is a non-believer.
For 10 years, between the ages of 20 and 30, I was a non-believer, but being raised a Catholic, I always kept in the back of my mind, the idea of a higher power (even though in that 10 year period i totally denied the possibility of a personal God).
Since then I have re-encountered Jesus and the Church. I don't see why this cannot happen to Manu.