Monster attack and defense in BIG are capped at 300 after the +150 from BIG is added (but before +ML effects are applied). HP just gets the +150, with no cap. Mafia knows about the +150 stats, but not about the cap, causing it to report incorrect monster stats on higher-end monsters, and calculate flyer done-ness incorrectly. (This also means that Wisnewski, the Man, and the NS aren't special cases.)
This changed some time after BIG went live, but didn't make it onto the wiki for a while. The wiki is still a bit confusing on this point, but I've done several BIG runs with a Monster Manuel, and can verify that monsters don't break 300 attack/defense unless the player is using +ML.
This changed some time after BIG went live, but didn't make it onto the wiki for a while. The wiki is still a bit confusing on this point, but I've done several BIG runs with a Monster Manuel, and can verify that monsters don't break 300 attack/defense unless the player is using +ML.