Sorry, bit morbid, but thinking about it, it seems wrong on so many levels.
Burying modern human remains in the past could cause an immense amount of confusion if discovered in the future, to say nothing of other traces of invasion into the past (the remains of a helicopter, anybody??) This occured to me before the death of Helen, but that just highlighted the potential future problems.
Also, what about the families of those lost in the past - wouldn't they want a burial of their loved ones? Are they just listed as "missing presumed dead" to stop any awkward questions? This might make sense for the military staff at the ARC, but what about civilians like Nick and Stephen?