Oak Bug!

So i was playing a match with (normal) Computers on prision and about half way thru the match Oak did his rez and his invicablility never wore off the rest of the match. . . . Anyone else have that happen?

 I don;t know how it happened all I know is he never left our healing crystal after he became not killable. and kept killing us over n over.  I havn't played as oak at all yet so is that like the last lvl of his rez spell or was this a bug?

If it is part of the ability It needs to change Fast.