I had significant misgivings about the app and it's efficacy. It is those misgivings that mean I don't believe this is an accurate representation.
Firstly, and perhaps most importantly, a positive case report on the app had to be backed by a PCR result, which required a code provided on a positive PCR test. A bad actor as you describe would have only one shot at a malicious shut down (and would actually need to be Covid+ to do it).
Secondly, the exposure limit was... generous. Proximity and duration had to be sufficient to form a close contact that would then be advised to self isolate and seek a test. People walking past a bad actor loitering outside a shopping centre would not meet this criteria. The shop keeper would...
...but shop keepers, retail staff et al by and large did not have the app. Employers were actively preventing their employees from downloading the application to prevent having to close for staff shortages while they were advised to isolate.
Ignoring all of this, you get into the crux of the app with the "check ins". All venues were meant to enforce the "check in" procedure - in actuality, it was pretty much only restaurants that did so. Even if you "checked in" to a venue, _you had no ability to check out_ so that if a positive case was reported on the same day you happened to be at a venue, even hours apart, you would be flagged. This meant that every positive venue ping had to be reviewed by a person, who would be tasked with reviewing which of the contacts in the venue should be contact traced. The criteria for doing so was opaque - and without the knowledge of what time people left vs arrived - and the actual device:device exposure being invisible to the contract tracer - we can only surmise that an element of inference and good old fashioned guess work was at play. And as was publicised at the time - the contract tracers found themselves with very little work to do.
>Should I also mention the Prime Minister was telling everyone to get onto Zoom for their meetings and then later on a zero click zero day exploit in Zoom surface which conveniently had given GCHQ enough time to hoover up data off plenty of systems. LOL
The Prime Minister has repeatedly demonstrated himself to be fundamentally incapable of understanding even the most basic aspects of his job, let alone technology. Hanlon's Razor comes to mind here.