I think ...
Written by Line
(1/18/2004 4:32 p.m.)
in consequence of the missive, Mr Bingley's actions, penned by kathleen (elder)
... you could read this both ways: that Bingley noticed his friend was upset, and tactfully cut his conversation short because of it, or that he really was oblivious to what happened, and left when he did by chance - your pick!