Ok, I know this is a once in a blue moon thing, but it's worth bringing up. Earlier today we had a fairly weak base up. I was the last one to shoot at it, and my shot happened to be the disabling round. I did not get a share of badges, my combat action was not recorded in the log. This also happened to me once on a shared NPC. There was an open slot, it was almost dead, I fired the killshot, and was not credited.

this is a known issue.... been like this as far as i can remember... not sure if it will ever get fixed...

The final shot on an npc or base never counts... if that is the person's only shot, they will not get credit (no drops, no badges, no raid)
Until Dan finally decides to fix this, you'll just have to remind all your legionmates periodically when they come across this issue.