Happily.
My understanding of the origanal post is the dammage occured in an obscure, wet part of the cave protected by a squeze and a climb. I've assumed its below the first ladder climb, because most of the cave is below that pitch. Either way it sounds to me like some caving kit (a decent head torch and helmet at the lest) and some knowlage would be necessary to reach the grotto. This leads me to think that cavers did it, as local YOs dont have either of these.
In my, far less extensive than yours of course, experiance of introducing peope to caving freshers tend to think 'small' is any thing less than 50cm squared, which reinforces my belife that the culpruit had a reasonable amount of experiance.
Stal has a financhial value, and cavers know this. I find it hard to belive (mainly because as goydanman sugessts i like thinking that cavers are all lovely and cuddly) that cavers would smash stall just for shits and giggles. because it seems more logical I think they broke off the stall to sell.
futher the origional post states small stuff was carried off, and the big stuff, which broke on impact with the floor, was left. I think the scumbags hadn't thoght theire calcite stealing through verry well, and hadnt anticipatrd the big stal would smash. when it did of course it lost its monetry value.
of course they could have done it because, like castelret they thought some nice speliotherms would enhance theire mantlepiece.
Do you also want me to expand on why I think lumping kids with lerning difficulties in with those with drug problems is (at best) intelectualy lazy?