Worth noting, I think, is that the trip to the alternate universe might actually have caused the real cluster**** at the node. Imagine, for a moment, that the 14th Battlegroup arrived through the node completely unharmed and undiverted. The UEF has not been put quite as much on edge from an additional several days' worth of probes arriving and departing without communication. The 14th is still 100% effective, and has no huge ethical split over their orders (to be sure there would be some anxiety and dissent, but not near enough to the level of ships flat out defecting). The Renjian sees an entire full strength battlegroup of sleek, impressive new vessels who's combat capabilities are completely unknown. Instead of charging into the teeth of the battlegroup, it withdraws without engaging any more than halfheartedly. The 16th Battlegroup doesn't immediately relieve the 14th, and the abortive First Battle of Neptune never happens, but the 14th instead jumps in around Earth and Lunar orbit relatively uncontested and with the strength of nearly an entire fleet of UEF frigates. Neither side wants to actually fight this close to the planet, where falling debris would kill potentially millions. Talks between the two sides commence, this time without the lives of several thousand dead naval personnel on both sides and with the GTVA in a hugely superior position. If the UEF fails to surrender, the 14th takes Earth effectively hostage. If they do, the GTVA has acheived all strategic goals going into the situation.
Instead, the Renjian saw a battered flotilla of disfigured and maimed ships. Her captain liked his chances based on the damage already sustained, and the order to stand down and prepare to be boarded could easily be a bluff from this so-called GTVA. If this ragged battlegroup is the pride of the GTVA navy, on the first re-contact with Earth, then it stands to reason that the GTVA could clearly be only months or years from complete and utter collapse. Against such decrepit ships, especially if they are of comparable firepower with his own Karuna, the Renjian's captain believes he can either stunt the invasion here, and return to Jupiter and the UEF a bona-fide war hero in an age where there are no real war heroes left, as well as bloodying the nose of the obviously already clearly shambled enemy, or he can hold them off long enough for the other ships of his squadron to arrive and finish off the crippled ships. Either way, by all appearances, the captain of the Renjian is poised to become the most famous man in the Sol system.
Appearances can be deceiving.