When can you call a Hellbomb?

I was playing a mission where we had to destroy Eggs, side objective was to destroy some buildings. As far as im aware only with special objectives it is possible to call in a hellbomb right?

I had a level 5 calling down a Hellbomb everytime when a bigger crowd of enemies were nearby or some bug holes or eggs. But that shouldnt be possible usually right?

It was fairly annoying to run for my life because the guy was activating them too ofc.

(Was annoyed from his wreckless use of strategems too, killing everyone too. To his defense: sometimes we were just a little too close.)

One time he even called one down at the evac spot and i saw him interacting with it. (I wasnt taking risks so i teamkilled him.-.) He said he was calling it for when we were about to leave...

I called him back in with reinforcement but still. It was fairly annoying to get a hellbomb every 100 meters.