Gallieni did not realize Shire was missing until nightfall.
He was busy all day, organizing reinforcements to be sent to Antwerp.
At this moment, the French Army was chasing the German Army along the entire front; the regular troops were all on the battlefield. The soldiers remaining at the rear were either just trained or still in training, sending these troops to reinforce Antwerp would be meaningless.
Therefore, Gallieni needed to comb through the entire front line to see where he could extract a few units without affecting the current battlefield advantage.
This could not be taken lightly; the Germans were not joking around. A slight oversight could see them launching a counterattack.
After finally squeezing out a division, he then had to plan their route, which was equally not easy. From walking to cars then to trains, and lastly bypassing the German defenses by sea route to Antwerp, thus he also needed to contact the navy for necessary protection.
