:Elen, it's clearly not a personal attack to you, because you wrote it.  As a (probably)  non-ASD person who knows you reasonably well I know you didn't mean ill by it.  But to an outside observer it can be interpreted in no other way, unless a serious face-value comment which would be bad for other reasons.  
 :But Sandy is not attacking you, despite the fact that you understandably may feel attacked.  She is saying, "this is a thing Arbs should not do, yet one did and nothing was done - can we handle this type of thing better? why was nothing done?  should there be a policy on this?"  and so forth. 
 :Had she said "a random arbitrator said..." it might have felt less personal.  I really doubt that she is "after your checkuser bit" - even though I have had issues with some of the cases you have checkusered, I think that it is a role you perform well and are well suited to, and I don't hear anyone saying to the contrary.  , .