I have worked in leagues with rules like this, and pretty universally this question is not addressed. Oh well.
If the only reason for stopping the clock was the blood situation, then I'd restart the clock as soon as the situation is resolved. If the spirit of the rule is to keep the clock running, let it run.
If you would normally have stopped the clock for the free throws (which is one of the common variations on this theme), then start as you normally would after the free throw.
Just my $0.02