Nowadays, swimmers are disqualified if they start early. Barring extenuating circumstances, there are no second chances. But this wasn't always the case in the MCSL.
My memory here is a little fuzzy, but I think in the very Old Days, each swimmer got two "freebies"--two false starts that were forgiven. If you false started, everyone was recalled and you tried again. You weren't disqualified until you left early for the third time...in one event. You can imagine how long it would take if each of six swimmers false started his or her two "free" times--those meets would still be going on. So the rule was changed to charge the false start to the entire field instead of the individual swimmer. The field got two "freebies," that is, the first and second person in the event to false start were forgiven--but the third one was disqualified. This inspired some older swimmers to play mind games, trying to get their competitors to false start and get disqualified. Or a swimmer might false start to, in effect, nail everyone to the "blocks."
My memory might be fuzzy on the details of the rule, but I clearly remember the false start rope. I got to hold one end of it at a B meet once when I wasn't swimming. We stood at about the flags, one person on either side of the pool, the rope stretched over the water--and yes, we dropped the rope in the pool when anyone false started, catching the swimmers before they got away. It was a wonder no one got hurt.
Now there are no recalls for false starts. The swimmers swim their race--and any who left early are informed when they finish that they have been disqualified.