Definitely not possible to fit the wrong way. The partition is shaped at the sides in a half moon at 45 degrees and the main plate is angled downwards. Hence, fitting any other way than correct means the partition protrudes the head which wouldn't allow the inlet manifold to be fitted - you'd have probably a 5mm gap and the injector wouldn't locate into the head.

I've got pictures and a video which I'll upload when I get home.

Matt