I was actually playing on the Evolstuff module when this happened. After looking at what the game was yelling at me for, I think this is a bug related to the base game.
One of the shamblers died just a few spaces from me, while the other one died while standing on acid, erasing its corpse.
The result: The game yelling at me with an error, the cache opening up, and the upper-right and lower-left items not appearing. Deimos Lab's cache has four items, yes?
And no, I didn't just pick up two items and called it an error. >_>

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Timestamp : 5/8/2013 16:25:43
Error level : ERROR
Message : Lua call OnKillAll caught ELuaException!
Call path : levels.deimos_lab.OnKillAll
Call params : ()
Error message : Call(levels.deimos_lab.OnKillAll) Lua error : lua\levels\\deimoslab.lua:179: attempt to index local 'special1' (a nil value)
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