How Widmore Found the Island by Bobby Sapphire

I've been trying to figure out why back in season 5 Widmore told Locke that if he didn't return to the island "The wrong side is going to win." Vozzek mentioned that this week but didn't really delve into it other than considering who Widmore may have been taking orders from.

But what if Widmore felt that the wrong side would win if he himself didn't return to the island. Clearly Widmore hasn't been able to find the island in all his years of exile so he could have used Locke to do just that. So he convinced Locke to go back to the island in the hospital and set things in motion. He could've known that Hawking would want Locke on the plane dead or alive. So to find the island, perhaps Widmore had Locke implanted with a GPS chip when he was in surgery in Tunisia and that's how he got there.