I dont think it was anything to do with anti - royalists!
Local rumour has it that a former pillar of the establishment who wanted to build some executive housing on Wearyall Hill found this unique way of venting his spleen.
The tree will sprout up again no problem - given time and the chance to do so.
I hear the Glastonbury folk are considering resurrecting the Wicker Man tradition when they catch the culprit.