The higher heat will make more un-fermentables sugars, you'll proboly have a heavy bodied beer. But the UF's would still show in the gravity.
There is an alternative to infusion mashing like you did, it is called "decoction mashing". In decoction, you actually boil 40% of your grains, and add it to the cool grains to raise the temp to mash. I'm sure your "creative surprise" caused a somewhat lower efficiency, but it's not terminal.
How did you sparge? (wash the sugar from the grains?). My guess is you left lots of sugars behind by not washing the grains properly.
So far, I've had more experience thinking than I've had brewing....you don't think they are mutually exclusive, do you?
72 batches so far,
48 wine, mostly Loquat, peach, plum, prickly pear
23 beers and ciders
1 Tequila, from a prickly pear wine experiment that didn't work. I call it "Prickly Heat"