Non MIR medical treatment

I have seen a few posts about members seeking medical care outside the MIR and then most responses say you have to go to MIR and disclose this. The reference i found is QR & O 34.13 (2) "An officer or non-commissioned member who has received medical care while absent from his base or unit shall report to the medical officer immediately on return"

My question is, what happens when members don't? Does the MIR somehow have access to other doctors records to know? What happens if a member gets caught?