Well there we go.
If you don't feel it was reasonable to suspect that he may have had a weapon on him, based on all the intelligence, the subjectivity can't be removed.
They could see his hands. Clearly. That was confirmed in court. Unless he was steering the car with his feet?
That's not the point being discussed: Rita said it was unreasonable for the police to suspect at the time that the driver may have had a weapon on his person.
That goes against all the evidence provided. The police stopped the car, like they did, because it was linked to two previous shootings in recent days.
Kaba was known to drive the car, known to have access to firearms, believed to have used one recently, had prior form of firearms offences and much more.
Was it unreasonable, at the time, for armed police to stop the car rather than non-armed officers? Ignore everything afterwards, with hindsight...
... was the decision at the time justifiable? That's how the law works.