'Rather than the dull metallic clang Higan had been expecting the thirty tonne A.S.P had caught Slimy between itself and the rough stone wall.'

This never actually happened though, as you explained to me that in fact your creature was conveniently perched with none of its body overhanging, which I accepted. However, you can't have that and still expect Higan to think the creature is stuck, the only reason he would have thought it was the difference in the Mech slamming into the wall.