None of us know (yet) what is in the Comey Memo, or if even if the Comey Memo exists. Comey has not made any comment or produced anything, yet. Comey has not claimed to have such a Memo. Both sides are speculating. If there is such a Memo, why did he not report it immediately to the DOJ? First of all, we don't know if he did or not. Second, who is the Attorney General? A close friend of Trump, the person allegedly discussed in the possible Memo. Third, if the Memo exists, it is part of an investigation that is ongoing. This is not a crime (if it occurred) where there is an imminent threat to someone's life or physical safety, where the suspect needs to be apprehended immediately to prevent a murder or injury. This is what the FBI does. It investigates and builds a case with piece after piece of evidence. They don't take the first scintilla of evidence, run to the DOJ, and stop their work. They continue to build a case, or if there is not sufficient evidence, drop it.
As to Putin's offer re the transcript of the private Oval Office meeting, are we at the point where we are willing to take the word of Russia on such a matter? Has Russia achieved such favored and trusted status with America that we look to Russia as the bringer of truth? Trump's tapes are what need to be produced to compare to the Comey Memo.