I don't have a bone in this fight, but when sample sizes are approaching N=1, you run the risk of evidence tampering, absent anonymity. You also enable political retaliation (ie, principla X supported Y, pull his funding...or oh look at him slip on a sidewalk...woops). Its credible, given the obvious anonymosity (all around), and the politicization of teachers unions (viz, wisconson, chicago, ect) that this consideration be taken into account. Again, this is not a "political point" (partisan sense) as it is a practical one about Naivete, and what desperate people do when they feel threatened.