Because the Antiphon had little need to stay at a pace that would sustain human lives it outstripped the Light Brigade and destroyed the Heebies' homeworld before the Brigade arrived. More than a little put out that their light years trek had been in vain the Light Brigade were in orbit around the now-dead planet when some kind of disaster struck. According to the official report from the ERCS Hunting Moon several of the ships, particularly those manned by known dymetricists, suddenly turned on their comrades and fired kinetic missiles at point-blank range. The fleet was savaged before the rogue ships could be destroyed. The few who made it back were reassigned to their own national fleets, forming such units as the Gemini Wing. The official explanation is that the Heebies had left behind some psychomorphic field generators that allowed them to inflict horrific delusions on the minds of some ship's crew. It is believed that the highly strung nature of the dymetricists left them particularly vulnerable to such weapons. The East Rim Consortium tried to impose a dymetricist registration act through the Union? as a precautionary measure but it was voted down.
Conspiracy nutcases have a field day with the destruction of the Light Brigade. One theory, currently popular, is that the Heebies never existed and that when some ships of the Light Brigade found out it was the East Rim Consortium portion of the unit that struck first, to prevent them informing the rest of the fleet. The fact that this theory rests on the testimony of Illych Un, brother of the infamous [Mikhail Un]?, who claimed to have been there (when the records show no sign of his presence) shows exactly how credible the claim is.