Help with analysis of crash please

My quad was flying in loiter, slight yaw to left and then tumbles down to crash. It actually recovered momentarily a few feet above the ground and then crashed. Recently loaded APM 3.2 RC5 but reloaded 3.1.5, set to defaults, and ran autotune.

There were no apparent hardware problems except those resulting from the impact.

At 26500 in attached log file RCOUT.chan1 and RCOUT.chan2 have sudden change which seems to precede Roll/DesRoll mismatch - not sure what this means.

Any suggestions appreciated, thanks much,

APM 3.1.5
OrangeRX receiver w/ 3DR multiplexor
Q Brain 4x25 esc
6000mAH 3s battery
AX-2810Q-750KV motors
Homemade frame

Certainly a hardware failure. Roll diverges from target at the exact same time as pitch.

Pitch forward, roll right. Front right powerplant (esc/motor/prop adapter/prop) failed.

Thanks for the feedback… i appreciate it!