The "humanity at its highest" refers to Bolt, yes. :)
EDIT:
The lowest was in reference to the look on Wallace Sprearman when he learns that, after having celebrated a bronze medal for several minutes (and he was really happy about it), he was being disqualified. It was a heart breaking look. :(
Churandy Martina who was celebrating a silver medal, was also disqualified for the same reason (steping on the inside line).