William and the Normans Fought at London Bridge

After the londoners were pushed back across the bridge, poitier tells us that the norman knights angrily burned all the buildings on the southern side of thames. Sutwock was burned to the ground in retribution. And curiously, despite the apparent victory, william and the bulk of his forces remained about 20 miles to the south and made no attempts to advance forward or cross london bridge. This is something that no other account mentions. It's possible that g vamiens just got this one wrong. But i also wonder if ge was just being a bit flowery with his language, and maybe trying to put a little polish on what william's tactic actually was,.