Thankfully, the use of the term CRB rather than DBS in the OP alerted me to the fact that this is a SIX YEAR OLD ZOMBIE THREAD
As a matter of genuine curiosity, that being the case, why would you reply to it to let us know you knew it was an old thread ? I'm not trying to be rude or funky, I'm genuinely curious.
The OP reading it or not reading it is not really the issue imo - she's not the one with policies and procedures to protect confidental information about vulnerable people. If it's a genuine alert then a parent, who may or may not pass the CRB to become a helper and who hasn't even been given a cursory 'this is what you do if you hear/see things you shouldn't' chat, has been given access to confidential information, and in a way that the school may not even realise that she (and potentially others) has read
This is one of the reasons that the thread caught my eye in the first place. There could be all kinds of reasons why the document was left on the desk, such as an emergency that needed to be dealt with, but none of this absolves the person that left the document on the desk. Even if they were just going to the loo for a minute, they should have put it out of harm's way. It should be a reflex action in one's mind in the same way it would be if one was reading a sexy e~mail on the computer from one's significant other or reading an important letter about your child's behaviour or whatever and the doorbell rang and friends came round. If it were me, I'd put the letter away or turn off the computer unless I was cool with people knowing the contents of what I was looking at.
At the same time, it's a poor excuse to say "it's human nature" or "at least the OP was honest." Lots of people with nefarious intent can be honest about certain matters and there are a number of dodgy aspects of human nature. It's the nature of a child not to share; that doesn't make it excusable. That's why we teach children to share. But you know, I'd even question if it is human nature to read a document that shouldn't be read because many people simply would not be interested.
The wondrous thing about the situation that the OP posed is that there are at least three very distinct ways that the matter could be taken.
I hate this. Think mn should lock threads down after so long
While I understand the view {I thought it myself initially when people asked why the thread had been resurrected}, when I thought about it again, I could find no compelling reason threads should be locked down. Bottom line really, if you don't want to get involved in it, don't get involved in it. Think of zombie threads the way one might think of an aeroplane flying through one's town at mid day ~ you may be aware it's there but you don't have to look up at it.