He is aware that the lack of pursuit means that Blucher is also likely to be marching west, but further to the south. Only one corps stands between Blucher and the campaign objective of Hanover.
General Poniatowski commands XIII corps at Peine. He is pleased with his small cavalry victory at Brunswick. But he is also concerned that it confirms Blucher is approaching.
There were three Prussian corps at Helmstedt, and neither Davout nor Poniatowski know how many are currently marching towards Peine. It is possible that two are moving towards Hanover, and one is left behind to guard their lines of communications to Magdeburg. But it is also possible that all three are moving on Peine.
Davout must soon decide whether it is still possible to hold Hanover, or whether he should retreat north to Hamburg. The loss of Hanover will cut his communications with Napoleon at Halle. Blucher has already defeated him at Magdeburg, and this would give him his second victory of the campaign.
Two of the four French corps are in good condition, but two are badly in need of rest. If Davout can concentrate his four corps he can turn the tide. But will Blucher give him the time he needs?