EDIT: THIS MIGHT BE A NEW METHOD... I DIDN'T SAW THE OTHER THREAD WHILE DOING THIS.
I noticed that a lot of friends who get the beer hat (and the happiness statue t-shirt and the Rockstar's t-shirt) bought all the outfits on the clothes store. I think this is some kind of glitch because I saw it by myself with my male character.
I checked the hats in the inventory menu and nothing, then this happened:
* Bought all the outfits
* Killed a friend with the Valentine's day weapon
* A normal crate was announced (didn't get it)
After doing that (and without notifications) I unlocked the three items (the two t-shirts and the hat), the beer hat was in my inventory, not in the store. A few friends said that after buying all the clothes get the beer hat in their stuff.
I'm not sure... and sorry if this was discovered already, just wanted to share this if you're not having luck with the crates. If someone else can prove it or had a similar experience please feel free to share.