[twexler]

Pretty sure there was a call out late in the countdown regarding arming the FTS.

[vibrolax]

They armed the FTS, as they would need that if the range safety officer needed to do that. But it was not needed or used by the RSO.

[JshWright]

Falcon 9 doesn't use an FTS manually triggered by an RSO. It uses an AFTS, which is controlled by the rocket itself.

My guess is it was armed for the early stages of the flight (when there was still a risk something could go seriously wrong and the rocket could start heading towards Orlandit), but it was disarmed (or just given very generous parameters) once the rocket was downrange a ways.