AIBU to ask the school to speak to these parents

[Skihound]

My child has to isolate for the 14 days as another child has tested positive - fair enough will follow guidelines. My child knows who it is and texted them to say hope ok they replied saying yes and got chatting turns out a postal test was ordered and they took it on Thursday (so was ordered before that to arrive) and positive was received Saturday, however the child was still at school via bus on FRIDAY, Aibu to ask the school to contact the family and reinforce the guidelines as surely this has put more at risk, I thought you should isolate from the moment a test is thought necessary, or am I wrong ?

The school will already have asked the positive child lots of questions about when symptoms started to help them identify which other children needed to isolate.
We have quite a list of questions to ask and have to relay the answers to PHE or the DfE.

Yes they should not have been at school while waiting on a test result. Maybe flag it with the school so others don't do the same

The school are very likely aware, I imagine they'll be an email in the next few days reinforcing the rules and reminding parents what the procedure is.