Dan,
Hi! I was re-reading this and had to call Bob when I read his answer. I called him (at dinner time) and we discussed. The HE OV and HE FP values are never the same number. There's a long winded reason for this and I can share later.
As for this particular issue we've agreed to modify the paragraph in the rules P 17.4 MINEFIELDS to the following.
MINEFIELDS
Engineers also lay mines. In Mein Panzer,
these minefields are considered to be a
mix of Antitank and Antipersonnel mines.
When any stand expends a Move Pip within
1" of a Mine Marker, they must roll to see if
they detonate the mines. Roll each time the
stand expends a Move Pip within range. On
a 1-10, the stand has struck a mine. An HE
attack with an OV = 2 or FP = 8 is immediately
worked out against that stand and any other
stands within ½" of that stand.
So in the example first given in a minefield attacks against vehicles are made w/ an HE OV 2 and attacks vs infantry are made w/ an HE FP 8.
Apologies for the confusion.