DSB concluded the missile that downed MH17 was a 9N314M. This was based on the three fragments found on cockpit and bodies of cockpit crew.
It would be logical to assume not only bow-tie shaped fragments were found, but also bow-tie shaped holes in the fuselage.
However there are no clear bow-tie shaped holes observed on the MH17 wreckage.
A possible explanation of the lack of bow-tie shaped holes could be that because of the cabin pressure leaking to the outside, and forces of the wind and thrust of the aircraft changed the shape of holes caused by fragments. I do not think this is a very likely explanation.
This because it would be true for other shapes as well. There are a couple of clear round holes caused by filler fragments as well as square holes. Additionally , some pieces of the structure of the cockpit are made of extra strong steel. These parts are less likely to change shape because of wind or pressure.
The Almaz Antey experiment where it exploded a missile on an IL86 aircraft on the ground clearly shows bow-tie shapes.