In hindsight they ignored the single biggest tell. The volume of small bets favored leave. However, bookie odds were towards remain. Why? Because bookies don't set odds on the number of bets. They set odds on the dollar amount at risk and bigger dollars were towards remain. The .01% ignored the people again and lost.
Yep, I remember reading last week that the odds were (roughly) 75% stay vs 25% leave, even though the actual bets (by volume) were 75% leave vs 25% stay. The difference was that the average "leave" bet was tiny, while the average "stay" bet was 5x times as big. In other words, the big bucks supporting "stay" apparently distorted the betting market significantly and apparently took a bath because of this vote.
I don't have a strong preference either way on this issue, but it's been a fascinating process to watch unfold. I'm still amazed "leave" managed to beat the big money, the big politicos and the big media. Whether (and how) it will hurt the UK in the end remains to be seen, nobody really knows how all this will play out.