Who's Glyndebourne's barking mad diva?

The Guardian's Charlotte Higgins has been winkling secrets out of Glyndebourne's costume department:

"You get normal ladies and diva ladies. Kiri Te Kanawa was a handful. We were doing an opera set in the 20s. She said, 'I don't do 20s; I hate 20s; I won't wear 20s.' She insisted on a 1930s dress. So she was in this long elegant bias-cut gown and everyone else was in a flapper dress. The reviewers noticed it and of course we got the blame. And you get the mad ones, of course. Last year we had one leading lady who kept barking. I think she thought she was a dog."

Who could the mystery barker be? The candidates:

• Sylvie Valayre (Macbeth)
• Rachel Harnisch (Così)
• Rinat Shaham (Così)
• Ruxandra Donose (La Cenerentola)
• Sarah Connolly (St Matthew Passion)
• Camilla Tilling (The Turn of the Screw)
• Nina Stemme (Tristan und Isolde)