The observation here is far too easily explained in other ways to be considered particularly strong evidence.
Memorizing a solution to a classic brainteaser is not the same as having the reasoning skills needed to solve it. Finding out separate solutions for related problems might allow someone to pattern-match, but not to understand. This is about as true for humans as for LLMs. Lots of people ace their courses, even at university level, while being left with questions that demonstrate a stunning lack of comprehension.
Memorizing a solution to a classic brainteaser is not the same as having the reasoning skills needed to solve it. Finding out separate solutions for related problems might allow someone to pattern-match, but not to understand. This is about as true for humans as for LLMs. Lots of people ace their courses, even at university level, while being left with questions that demonstrate a stunning lack of comprehension.