Sun explosion follows comet crash. Did the comet trigger this giant CME?

There's no known mechanism for a comet to cause a magnetic instability.  This is the second time scientists have been puzzled by what looks like a causal link.   The ten second gif of a coronagraph covers nine hours of action speeded up.  Posted October 3rd at Space Weather with some additional information.

On July 5, 2011, the unnamed comet appeared to interact with plasma and magnetic fields in its surroundings as it fell apart. Could a puny comet cause a magnetic instability that might propagate and blossom into a impressive CME? The question is not so crazy as it once seemed to be.

 
A coronagraph is a telescope that can see things very close to the Sun. It uses a disk to block the Sun's bright surface, revealing the faint solar corona, stars, etc.