pumped up with adrenaline... maybe (but i think no, he got the available help to lift Bosma), but at the time when they moved the body around, adrenaline would've been long gone, jmo.
edit: and also since MS has divulged that DM had oxy's, MS says he refused to move Bosma (pffffft), DM could've easily have swayed him by offering up a bunch of them orange guys (and/or more weed) to MS, jmo.
edit2: MS has also said that DM hid different drugs in different locations in his house, it would've been a virtual candy store to MS, jmo.