He might or might not have given info to the Russians but to believe that it happened in such a blatant and overt fashion is rather naive. These calls with foreign leaders are monitored, that's why the first impeachment happened, after asking favours from Zelensky(seems ages ago). Furthermore, a president requesting a list of all agents is practically unheard of, since he could not have any logical purpose for it. It would have probably triggered absolute mayhem even greater than what happened. A more probable way for transfer of information is through 3rd parties appointed by him in the IC.