I used search function but nothing; sorry.
Confirmed in 16w39a
Well, I make a schematic.
[MOB] [LAVA] [PLAYER]
Player shoots in the lava with bow:[MOB] [LAVA] [ARROW] [PLAYER]
\/[MOB] [ARROW BURNED] [LAVA] [PLAYER]
And hit the mob:[MOB SHOOTED] [LAVA] [PLAYER]
But, the mob is burned too a two chances.
Xerces MC
I used search function but nothing; sorry.