Police and firefighters battle to prevent damage cause by anti-US film demo

The transcript involves a discussion about an intense situation where emotions are high. It begins with a question about what happened, followed by a description of someone being intense and out of control. The conversation then shifts to a resolution where control is regained, and an achievement is acknowledged, though it ends with a negation.

How do you interpret the overall tone of the dialogue?

What might the speaker mean by 'I did it. No.'?