http://news.yahoo.com/video/science-15749654/comet-baffles-nasa-scientists-27898335.html

Any guesses on what the tail of this comet is doing during and after passing through the suns atmosphere?

I would think the tail disappearing would be due to the immense heat it is sitting in when that close to the sun. It gets vaporized before it gets to form.

That sounds reasonable. I was venturing to guess that the spiral zig-zag as it approached the sun could indicate it was made of some ferromagnetic material which could possible be affected by the field lines from the sun.

I think your guess sounds good for the exit trail.

The coma is essentially water vapour which has sublimated due to the comet's proximity to the Sun. Not only is the temperature an issue, but given that the comet passed so close I'd suggest there would be difficulty optically differentiating the coma from the corona.

It is an interesting event though. Seems the comet was a lot more massive than previously thought.