Your ignorance of the methodology doesn't constitute use of fuzzy math on their part.
let me give you a hint about the methodology: They ask people. Crazy, right?!
My ignorance? Look in the mirror dude. YOU have no idea on their "methodology", yet because they "say so", it must be true. Now go drink some more of that orange Kool-Aid.
Where do they get these people?
Yes, your ignorance. I know exactly what the methodology is - in fact, I've filled out paperwork as part of the calculation.
The methodology is to survey recipients of stimulus funds with two straightforward questions. Paraphrased:
1) how many people did you hire because of the project funded by ARRA funding?
2) how many positions were maintained due to ARRA funding that otherwise would have been let go?
These basic questions are part of every ARRA report.
Now go drink a beer, relax and educate yourself.