Evocative Vocative Disambiguation

I kept wondering why the film is called Sebastiane when Sebastian's Latin name would pretty clearly be Sebastianus. Then it struck me that this is the vocative ... O Sebastian. The vocative case of a second declension noun in -us is -e. So the name of the film addresses Sebastian, and this supports, I would argue, the notion that the film is really about Severus as a stand-in for the audience. He/we cry out, O Sebastian, and then we arrow him.

Other posts on Sebastiane:
More Thoughts on Sebastian
Sebastian: Patron Saint of Gay Men