Plane had a tail strike before:
Doomed Russian jet that crashed in Egypt suffered 'tail strike' in 2001 - The Economic Times
there is another case where a plane broke apart 22 years later because of that:
https://en.wikipedia.org/wiki/China_Airlines_Flight_611
and the tail in this case was found closest to the airport, means it broke off first
that would be a viable, non-terrorist explanation