This year's non conference slate included William and Mary, ODU, and ND (which was a forced game). Just scrolling through the past few years, it's a couple doormats and a respectable non conference opponent as their typical schedule. Not hard to rack up win % against doormats.
Also I don't know I agree with the validity of the stat (unless you meant to say home game).
Just looking a few years back I see loses to OSU, Tenn, East Car, and ODU. That's 4 losses.