Safety in Numbers

Unsure how many cameras but the police gained access to the congestion charge ANPR cameras.

https://tfl.gov.uk/corporate/privacy-and-cookies/road-user-charging
Police access to ANPR cameras
In 2012 the Mayor of London's Crime Manifesto included a commitment to instruct TfL to give the Metropolitan Police Service (MPS) direct real time access to the Automatic Number Plate Recognition (ANPR) cameras we use to enforce our Road User Charging schemes, for the purposes of preventing and detecting crime.
Following a public consultation, the MPS was given access to this data in 2015. No images of vehicles are provided. In effect, TfL and the MPS now share the network of Road User Charging cameras.
This was an expansion of a pre-existing arrangement with the MPS established in 2007, under which they were given access to TfL's ANPR data specifically for the purpose of using it to safeguard national security. This arrangement was approved by the Home Secretary, who signed a certificate confirming that TfL, and the MPS, are exempt from certain provisions of the Data Protection Act 1998 for that purpose.

Not at all. The decline, welcome as it it, is down to a combination of factors and can't solely be attributed to rising cyclist numbers at this time. If that were true then we wouldn't see the statistics reported in this table here: https://en.wikipedia.org/wiki/Cycling_in_London#Statistics

There's continual growth in cycling numbers between 1999 and 2014 but there are three observable spikes in KSIs. I'm hoping that you aren't going to call those counter-flukes because that really isn't the case. What we can't determine is that the increase in numbers didn't not provide additional safety for cyclists.

Driver behaviour is the greatest cause of KSIs for all road users. Congestion exacerbates bad behaviour. This is actually observable pretty much anywhere, not just drivers on the road. Take a look at cyclists who come around the front of a group at a red light despite arriving later. Take a look at human behaviour when there's an evacuation in a crowded area. Take a look at skiers trying to get on a busy chair lift. It happens all the time. As soon as humans get into congestion conditions, a proportion of them will resort to self-interest and attempt to exploit opportunities accepting a compromise on safety, particularly the safety of others.

Opportunity is linked to infrastructure because if it prevents a driver from causing harm regardless of their behaviour. Likelihood is linked to behaviour because when presented with an opportunity, it's the road user behaviour that will determine whether something then does happen.