Weapon Disappears In the Final Mission

1 of my snipers had a Gungnir, but switched to use handgun on worms. When I came back to this unit, the Gungnir no longer shows in their inventory. It just disappeared. It’s not on the ground, nor any other unit’s inventory.

In this map you have a few Chirons bombing your units, if they hit the snipers they can’t destroy weapons, if that was not the case then it’s a bug. I didn’t suffer the bug, just a bomb destroy my Raven, I had both SR for every sniper

Only attacks on the units up to this point was Goo blobs and fireworms. The latter where all dealt with. The unit affected has his rifle, but opted not to waste the ammo on a worm, so switched to pistol. Then the rifle was gone. I did F12 bug report it.