Are you 100% sure of that? I just downloaded the map and checked, everything looks fine. You can download the map again and use the same character if you need to get through that part. Obviously some chests will be refilled, but it's not a huge deal.Just a heads up you have some wire broken in the map, the start of the water temple can't be opened, and the brain of Cthulhu fight does't start ethier.
Sorry it glitched out. Were you playing single or multiplayer? Sometimes the mechanics don't sync right in multiplayer.