To be technical, what he read wasn't prompt, it's part of the AI's response to the prompt.
But yes, it's a giant tell that politician used AI to write his speech, and he didn't thoroughly edit the response when preparing the final draft.
Encouraging that news.com.au (a Rupert Murdoch shop) staff can't tell between AI prompt and response...
No, that politician trusted some poorly paid staff to write a boring procedural speech while he was doing something (hopefully more useful).
The staff used an LLM and did not bother to check (or got their check wrong.)
One of them is guilty, the other one is responsible, the conséquence should be in proportion to the gravity.