Dragonspet
Not sure that you have got that the right way around. The wing tank pumps would have been on, because there was fuel in them, but the centre tank pumps should have been off because that was empty. The explosion was in the centre tank, which was “empty” (ie residual fuel only) and the centre tank pumps were on.
In a nutshell, the AD is saying don’t run the centre tanks pumps dry. Most qualified personnel wouldn’t let it happen, but obviously as it has happened at least twice. Boeing has felt the need to bring out an AD on the subject, if only to serve as a reminder about good operating practices and I suppose for product liability reasons.
S & L
PS I couldn’t get your link to work either.