I am building an adventure map and a noticed that the setblock command derped up...i put in the coordinates for the block and it placed the block a few blocks away.
i was at the coords -1054 46 -1038 (or something like that)
im not sure if it were because of the coords i was at or something else
i do not know if it does the same for other commands...

to trigger the bug:
go to the coords mentioned above and in a command block do:
/setblock X Y Z minecraft:redstone_block
it will put the block a few blocks away...