Can the UCAT people mark your test wrong?

Hey everyone, i know me saying this would make me sound like an egotistical bastærd, but can the UCAT people mark or scale your test wrong? I was averaging 2.7-8 on medify consistently. But after sitting the test I received a 2630. Walking out of that test i thought i aced QR and AR, and pretty good in DM. But a 2640!!?! I was bewildered. Last year I got 2750, and averaged 2.3-4 on medify. So this leaves me questioning everything, and the process. Let me know if you have heard anything similar.

Thanks