The UK’s botched contact-tracing COVID app has run into its latest hurdle — this time the fact that thousands of people have been possibly exposed to coronavirus without being told that this is the case.
The reason for this is that the app used the wrong risk threshold to send out warnings. In essence, it assumed that people were too far away for transmission to be possible — even when they weren’t. As a result, “shockingly low” numbers of people received warnings.