How do you know the evidence existed if it had been suppressed?
Bits come out, like the 100+ people who saw a light go from the surface level up before the plane exploded--from a variety of vantage points on land, in the air, and on the water.
Like the additional debris field at 90 degrees to the flight path (probably indicating a missile hit).
Like PETN residues on pieces of fabric from the plane's interior.
Like to have an explosion in a fuel tank, you need just the right fuel/air mixture, and an ignition source. Jet fuel is formulated to prevent explosions.
Not particularly good at security, the pieces of the picture which were revealed give enough when the dots are connected to yield a general picture of what really happened, but even more so, they reveal what likely did not.