I wrote to PETA and got a response identical to the one posted here by Bill Cline.
I explained that I was extremely upset that PETA killed the animals in the first place - I was not overly concerned about where they put the dead bodies after the fact.
I received the "We're so sorry that we offended you by throwing the bodies in the dumpster" a second time, with a letter saying that she would not discuss the issue with me any further, as PETA had better things to do with their time.
I wonder what an "undercover investigation" of PETA might show up?