As I had posted this on Reddit, people reported lots of other similar bugged loot spawns like the green house, f.e.:
-cars (no loot)
-castles (loot spawns high in the air)
-other houses with bugged loot spawns
-etc
For more reports on this issue check the reddit post to this:
http://www.reddit.com/r/dayz/comments/1xw4wg/devs_i_found_out_why_those_green_house_never_have/