In order to be a man of straw, it would have to claim that AI "just is" a well-poisoning machine (in the literal sense of a machine that inserts poison into a hole in the ground containing H2O).
Not AI as a whole. Particular activities to do with AI which would generally be deemed not only dangerous, but also not having any clear non-malicious purpose.
So if there was a strawman argument here at all, it's literally the one you just made!
In order to be a man of straw, it would have to claim that AI "just is" a well-poisoning machine (in the literal sense of a machine that inserts poison into a hole in the ground containing H2O).
Now, that alone does not mean that it goes through; the analogy works as an intuition pump, and those can be flakey (see https://en.wikipedia.org/wiki/Intuition_pump)
But nor does it mean that a fallacy has been committed