Was Bianca Jagger Flashing at Barbican "Einstein on the Beach"?

Bianca, seen here at the Théâtre de France,
in a March 1974 photo shoot for Vogue UK.

"Last Friday, the theatre critic Mark Shenton was distracted from a five-hour performance of Philip Glass's opera Einstein on the Beach by a woman in his row taking photographs with a flash. It turned out to be Bianca Jagger. She had been snapping in defiance, Shenton claims, of complaints from those around her. Jagger has since said that others were taking pictures, too, adding that Shenton insulted and assaulted her. (He denies the latter, but admits the former with some pride.) The rules of behaviour in today's theatre audiences certainly seem to have changed. So, in the spirit of public service, and after consultation with Guardian critics, here is a new code of conduct." [Source] Read more details about the evening here.