I had the fortune of attending my first and only Mahler8 under Zander with the BPO in the late 90s. Great great concert. I remember him being hailed as a great Mahlerian back then, I haven't really kept up with the scene, but always heard great things critically and my own ears enjoyed his music. In addition to his work as a musician it was well known that he was an immense contributor to the musical development of the youth of Boston.
It sounds extremely political, like this is an excuse to get rid of him. If it was just the issue of this videographer, they would just fire him and move on, but to lay the blame on Zander doesn't really make any sense, if anything you would blame the administration, not the talent.
I have no idea how Zander is as a person, if his students love him or not, but if they do I'm sure they and their parents will form some sort of campaign of support. If not, well then.....