In 2006, we (Maine) ran an experimental rule reducing OPI w/LOD to IR as this often was the case of a wide-out unintentionally lining up on the LOS and covering the TE. If the TE ran a pass pattern and touched a forward pass it was OPI. I felt it was an over kill. There was also a proposal on the docket to turn a forward pass that is grabbed/muffed/ batted by an IR behind LOS as illegal touching instead of IFP. We compromised (sorta' like we see every day in politics
) and made both illegal touching. Being a loose ball play, with previous spot enforcement, if the IR was beyond LOS the enforcement was previous spot. If the IR was behind the LOS , the spot of the foul would become the enforcement spot under the 'all-but-one'.
The list of exceptions do not list illegal touching. I assume that means the enforcement spot to be the previous spot.