Gotcha. When you say you ended up with almost 3 extra gallons of wort, do you mean post boil? What was your total pre boil volume, and your total post boil volume?
It's likely two things: 1. You oversparged. When mashing and fly sparging, the volume of water you put in is greater than the volume of wort you take out. You don't need to run your mash tun dry; just stop collecting when you reach your pre boil volume (in your example, 7.37 gal) and/or pre boil gravity. 2. Sounds like this profile is set up for your buddy's equipment setup. If you are using a different equipment setup, the equipment profile might be different (specifically here, volume losses due to boil off, trub loss, etc). You may need to "dial in" your equipment in Beersmith.