It's a while since I was involved in Advanced training but the first thing we'd discuss is Information - receiving it through vision/hearing and giving it through indicators/brake lights etc. (The rest was Position, Speed, Gear, Acceleration "IPSGA").
So, if there's no one around to "give" the information to then using say, an indication when there's no one there was classed as a failure to receive (and process) information correctly. i.e acting by rote rather than by the situation. This point was agreed by a Police Examiner and would lose a candidate marks on their assessment.
Conversely failing to indicate when the was someone around to see it was similarly a failure to receive (and process) information and would lose a candidate marks on their assessment.
Serious concentration and skill these Police drivers/riders
.
Andy