That article doesn't prove what he's saying.
Seeing a spike in google searches for “what happens if we leave the EU” doesn't indicate whether the searches were initiated by Remainers, Leavers, or non-voters. Besides, a 250% spike on the heels of a major event is't really much. The knowledagebale voters had months to research the implications while the ignorant ones may have decided to research the impact only upon passing.
First of all, it's not an article, it's primarily a collection of links to other articles. Second of all, I never said it's a proof. In fact, in the link you'll see they wrote:
There’s no proof the spike means the people who actually voted in the referendum had no idea what would happen. (Let’s hope. Then again, the “leave” campaigners are already saying the results are not their fault.)
Given that turnout was about 72%, it’s likely that the frantic googlers are those other 28% who didn’t think the daily headlines worldwide and massive campaigns with celebrities involved were worth paying attention to at all—which isn’t really much consolation.
Basically, I don't actually care whether it was the remain, leave, or undecided voters (or even all 3) that didn't research it properly beforehand. The point is that had they researched it they'd have at least been making an informed decision. I happen to personally believe that the leave argument is more credible to the uninformed.