To "deceive more people"? Take off the rage goggles and consider other alternatives like "they normally type like this. so when they had the LLM edit it that's how it remained", "because they normally type like this, its in the memory that's how 1st person text should be generated", or even just "because that's how they type, that's why they prompted it that way" before accusing blatant 1 mm deep attempts at deception as the driver.

But yes, the rule about LLM generated text should at least be abided by and preferably enforced regardless if the intent was malicious.