Are canned, unsweetened elderberries supposed to smell like blue cheese?

I know someone who recently water bath canned some blended-up elderberries without added sugar (it should be noted that elderberries aren't sweet in the first place). We ate a jar of it that didn't seal; we ate it over the course of a couple weeks or so. We opened another (a sealed one) today, and when I put it in my mouth, I noticed that it smelled quite fragrantly to my nose of blue cheese (or smelly feet). Is this normal? The jar that didn't seal didn't smell at all like blue cheese (directly after canning).

It seems that elderberries are thought to have an unpleasant smell, based on the idea that telling someone they smell like elderberries is an insult (unless that just has to do with alcohol, as one person thought).

I'm a little worried that the pH was too high. People say you can water-bath can elderberries, but I'm not sure if this is just an assumption based on other berries. They don't taste very acidic, and the lack of sugar seems concerning.

If it is actually Brevibacterium linens causing the smell, it would seem rather astonishing, since it's not supposed to survive canning temperatures. The jar did seem to seal correctly, and popped when opened.

Re-cooking the smelly berries did not fully remove the smell.