That headline at the freedom outpost is very misleading. There is nothing in the transcript to indicate that no one died until SWAT entered.
They do say, however, that no more shots were fired after the officers were told to stop and wait for SWAT.
Correction: No more shots were fired after the officers were told to wait for SWAT - until the SWAT team entry.
There was clearly enough time for the shooter to kill 49 and wound 53 from the time the event started until the officers heard the last shot inside, perhaps 15 to 20 minutes later.