I think you may be overlooking the obvious in an attempt to prove the unlikely.
Think it through: The ailerons fluttered (flutter isn't a function of speed as much as it is of slop in linkage... with slop, flutter can happen anytime).
So, the ailerons fluttered, stripped out both ail servo gears which made things suddenly interesting.
Then, you say you "lost elevator control", but more likely, you stalled the aircraft and snapped it into the ground (a slow speed stall/snap would make it "feel" like you lost elevator control. Keep in mind that with the aileron servos stripped, you could easily have had some unintentional spoiler action going on, reducing lift at the speed you had become used to on landing.
Then you say you checked it out and the receiver was dead (bad crystal). That's a surprise? The crystal is the most fragile component in the receiver and even a mild crash with trash a crystal but leave the rest of the receiver in fine shape.
That's the most obvious, simplest scenario as to what actually led to the aircraft's demise.
Highflight