whats this?

[NeoDrgnMech]

An explosion rocks overhead as a Terran Republic soldier prepares for an attack next to an abandoned Deliverer.

The reason it isn't firing at him is cause there's no one in it.

And he might not care about it because there could be more important stuff to worry about (it didn't necessarily say that big boom came from him...). Or, he could be waiting for a buddy to come hack it.