Diversification
That is a powerful and important point. The HF antenna is in the leading edge of the V/Stab, I believe about two metres up. Without calling it a "Long Shot", I would suggest the damage could have been caused by a loss of the Radome. The leading edge of the V/S is perennially pock marked with debris, ice, hail, birds, etc. The photo of the a/c taken just before the fatal flight shows evidence of this. Radomes are notorious for damage, after all, they lead the pack of the entire airframe. I think lightning is a long shot, but there are numerous occasions where the radome is shattered or even lost after a strike. The fact that they are constructed of composites (Non-Conducting), makes them even more prone to damage from an electric charge. Electrons get pissed when they have to "walk" instead of following a suitable metallic path.
rgds'
bear