At that time in Christian West, the notion of "Judeo-Christianity" would be considered an oxymoron. But it is possible that the general is question is in fact alluding to that era from ignorance.
> What has become known as the People's Crusade passed through Germany and indulged in wide-ranging anti-Jewish activities, including the Rhineland massacres.
Yes, as it's more often than not used. It's basically "what evolved as Christiatity, through the adoption of Judean-originating ways of belief" (as opposed to pagan ones).
Medieval crusaders would have balked at the idea that Jewish and Christian values could have any form of harmony.
"Judeo-Christianity here just means Old+New testament. They just didn't use that terminology back then, but the notion was very much the same".
The didn't say "Old+New testament" but it meant exactly that, what scholars for a couple of centuries now refer to as "judeo-christian".