I agree there's cases that humans will handle better, but there's also cases where the apps will do better too, and I wouldn't be surprised if it was a wash (so

I agree there's cases that humans will handle better, but there's also cases where the apps will do better too, and I wouldn't be surprised if it was a wash (soon hopefully we'll have some actual research on this!). For example, in most situations where you're near an anonymous stranger, manual tracing is going to have a lot of trouble. That's a _lot_ of cases. You're almost certainly not going to be able to hunt down the person you sat next to on the metro for half an hour, or a stranger who came into your shop to ask some questions yesterday. Apps plausibly could trace them. That's before you start thinking about simple forgetfulness. Who did you sit next to in the company meeting a week ago? Assuming people actually use contact tracing apps (TBC...), then many of those otherwise untraceable contacts can be picked up.