Hit a rock and now have oil smoke through exhaust

I was in the mountains in B.C. behind a semi, coming through a pass there
was fallen rock on the road that I didn't see until it came out from under the
semi in front of me.  It hit hard underneath the car and smashed the hard
plastic cowling that runs along the front under the engine and tore it and
the other undercar cover completely off as well as some other body
damage.  Since that has happened I am suddenly burning oil terribly
through the exhaust system.  I believe it is coming from the turbo waste
gate problem I have read about.  I have the are in to the mechanics for
insurance repair and he is telling me it has nothing to do with hitting the
rocks.  I need a professional opinion as to whether this kind of impact can
cause the waste gate problem, because it was non existent before the
collision, but now is very bad and embarrassing.  Also I now have coolant
leaking out of the car and it reeks, they are telling me that this has nothing
to do with the impact either.  PLEASE HELP!!