I think this "tensile test piece" is the tab of the powerfet, active part
completely blown off the tab and as no trace of die, presumably isolated tab
, as also on a ground plane. Or could the 0V line be switched? Cannot even
see what orientation as no top-side traces to G,S,D and no pads seen.
Desoldering the tab and then desolder wicking does not totally remove the
solder and just a neat solder rectangle on the pcb, very odd.