Game Mechanics: invisible corpse

[chayes]

crushbone
lvl 9 druid (treeformed)
trained at zoneline
on corpse run, my body was invisible.
it was present as i could /corpse it.
i looted it by looking down, /corpse, clicky until lootable

i believe there was an issue with transforming from treeform to normal corpse
Probably repeatable, though I dare not attempt on purpose :-/