Subsequent parks missing from logs

I set up hdapsd and wanted to verify it is working.
For this I started it with --verbose, kept something writing to the disk and let the device fall repeatedly (of course gently breaking it instead of letting it hit the floor).
Each time could hear the disk head move, then park as it entered free fall, then quickly start to move again, but this is the output I got:

Sat Mar 30 18:45:31 2019: Starting hdapsd
Sat Mar 30 18:45:31 2019: WARNING: You did not supply any devices to protect, trying autodetection.
Sat Mar 30 18:45:31 2019: Adding autodetected device: sdb
Sat Mar 30 18:45:31 2019: Trying INTERFACE_HDAPS
Sat Mar 30 18:45:31 2019: Trying INTERFACE_AMS
Sat Mar 30 18:45:31 2019: Trying INTERFACE_FREEFALL
Sat Mar 30 18:45:31 2019: Selected interface: FREEFALL
Sat Mar 30 18:45:31 2019: Uses hardware logic from /dev/freefall
disk: sdb
threshold: 15
read_method: hardware-logic
sampling_rate: 50
HW=1
Sat Mar 30 18:46:18 2019: parking
HW=1
HW=1
HW=1
HW=1
HW=1
HW=1

Running hdapsd without --verbose and with --syslog, as one would with a daemon, means I get no indication that the disk was parked after the first time, which hardly seems intentional.