Whatever you did to customize your league settings is the issue here; you seemed to set the league to have no playoffs at all, as you can see at the bottom-right corner of your league's Rules page (linked below). Horrifyingly, this change appears to have been made after your league's playoff schedule had already been locked in and played out, which is why Terry's Holy Terrors played more games than Phirst and Goal: the games played in Weeks 15 & 16 probably WERE playoff games at the time, but the league rules were then changed to have no playoffs at all, and the Fleaflicker site seems to have changed those Week 15/16 playoff games to just regular season games retroactively.

You also cannot change playoff schedule rules this late in the league year (probably in an effort to avoid situations just like this one!), so I think you're pretty much out of luck here - Phirst and Goal are technically the champions by virtue of having the best record in a league with no playoffs. I'd recommend a hearty apology to the league and a pledge not to mess with that stuff once the playoffs have started in the future.