It wasn't just the T shirt, Cindy unfurled a banner. We're lucky she didn't throw a bucket of blood.
What's the source for the banner? I can't find more than 1 news article which doesn't mention the T-shirt, and it's old (yesterday). I think the banner thing was an old Reuters report that got it wrong.
She should have just been escorted out, quietly and without fuss, to avoid her yap trigger.