"In fact, he did what any person in his shoes would do."

No. Not true. A number of Republicans have already come out to say that this was not a smart thing to do:

"“I’ve been involved in 9 presidential campaigns ... never happened, never would happen for all kinds of reasons,” said GOP consultant John Weaver, who advised the White House bids by Ohio Gov. John Kasich and Sen. John McCain of Arizona.

Rick Tyler, a former top aide to the presidential campaign of Sen. Ted Cruz Texas, said he would have called the FBI if approached by a foreign agent from an adversarial nation like Russia.

“Senior presidential campaign officials don’t take meetings with nameless people. Doesn’t happen,” Tyler said."

and other Republicans have said similar things. What part of the idea of "collusion" don't you understand?