I think the Wiki misrepresents the actual dialogue a bit:
This is what Trudy actually says:
To me, that's more of an indication that Victor never really had an "owner" and that the townspeople are misremembering or just repeating an oft-told rumor. My guess is that Victor was always a scout for House. He's an AI after all, not a Securitron (or at least not a specific securitron), so he would have always been dialed into the Lucky 38 mainframe and network: even before House emerged.
Who knows, maybe he made up the rumor himself to have some sort of cover. Needless to say though I think his "owner" was always House.