I don't think the argument given is circular (perhaps poorly expressed, but it's hard to be both succinct and precise).
The Argument from Altruism says that altruistic behaviour cannot have evolved by natural selection, because natural selection only favours selfish behaviours.
The response in "flaw 2" points out that altruism is not necessarily an adaptive behaviour. It could be a non-adaptive consequence (what Stephen Jay Gould calls a spandrel) of another feature, namely, general intelligence.
We don't have to explain why general intelligence leads to altruism in order to establish that this is a flaw in the Argument from Altruism, merely observe that it does.
no subject
The Argument from Altruism says that altruistic behaviour cannot have evolved by natural selection, because natural selection only favours selfish behaviours.
The response in "flaw 2" points out that altruism is not necessarily an adaptive behaviour. It could be a non-adaptive consequence (what Stephen Jay Gould calls a spandrel) of another feature, namely, general intelligence.
We don't have to explain why general intelligence leads to altruism in order to establish that this is a flaw in the Argument from Altruism, merely observe that it does.