Why is this Lanky Ship alone and acting unusually?

In the battle in the Fomalhaut system after the Solar System is attacked and Grayson is stranded with a small portion of the fleet, the Lanky seed-ship behaves in some very strange ways. It deposits its seed-pods on the surface of the SRA moon, them run off after a Russian ship without first deploying the minefields and planetary defense measures the Lankies usually employ.

On top of that they didn’t gas the colonists like they usually do, or set up terraformers, which allowed the combined fleets to take back the moon.

For whatever reason, the Lanky seed ship we destroyed in the Fomalhaut system by flying a water-laden freighter into it never deployed defensive minefields around the SRA colony moon before they set out for New Svalbard. They arrived in orbit, dumped their colony pods onto the surface, and went straight after the single Russian unit in orbit, the hapless cruiser whose futile run and subsequent destruction alerted us to the Lanky presence in the system to begin with. Now the SRA moon is crawling with Lanky settlers, but they have no overhead defenses, and no seed ship in orbit to keep our ships away. We can finally fight them on somewhat even terms, with the airpower and spaceborne artillery we’re usually denied on Lanky worlds.

There are survivors all over the SRA colony. The Lankies have been on the surface for less than three weeks, and while they’ve methodically wrecked the human infrastructure on the moon wherever they went, they didn’t use the nerve-gas pods they usually employ when scraping us off one of our colonies.
_{Angles of Attack: Prologue}

Emphasis mine.

Is there any indication why the Lanky ship was acting usually?