A late night 10K

I signed up to run a 10K tonight with a bunch of friends. It was a late night race (starts at 10:00) and runs along legacy parkway. A 10K is 6.2 miles. This route, which was supposedly a 10K was 8.5 miles. I'm a race director myself and I really don't know how you could be off by 2.3 miles!! But, I'm still thankful for the race. It was fun. I'm also thankful that I'm training to run longer than 10K right now so a couple extra miles wasn't too big if a deal!