I know it has become fashionable in certain circles lately to demonize Churchill but I won't buy this until I see some documentation.
I am not part of the circles you describe, and don’t see the possibility as so odd. Churchill in any event would have acted in british interests, not american, and it was certainly in their interests to get us into the war as soon as possible.
It is fact that he was first lord of the admiralty until May 1915.
In any event, if we are waiting for ‘documentation’ aside from the above you might have found a mechanism to defer the matter for decades if not centuries. In the meantime, intelligent people can at least speculate in some circles.
"Certain circles" means Pat Buchanan and a couple of bloggers who own pit bulls and write Letters To The Editor in green ink.