Covid worry

Hi all
So my partner and I have been strictly self isolating since March and last night my partner, for the first time since, went for an outdoors, socially distanced meal with a couple of friends

Now, this morning, one guy messages everyone to let them know that his nephew (who he spends a lot of time looking after) has been sent home from school with symptoms. So of course I'm freaking out.

The guy called nhs direct who are unconcerned. Due to where we live the likelihood of it being covid is low. The boys temp has gone down with paracetamol and ibuprofen and my partner's friend has no symptoms.

I'm going to stay with my parents for two weeks,but I'm so worried about my partner. He feels awful about it. It's literally the first time he's seen another person aside from me or my parents since March and this happens.

Its fine though, right? The chance is incredibly slim he will have got covid?