If someone chooses to bait Xtians by using the word "fact" instead of "theory", does anybody really care? Stop fueling the flames. Is this a sandbox or an adult support group / discussion forum?
As far as using 'common vernacular' as an explanation, I say fuddle-duddle! If I am going to TEACH something, I shall use the correct terms. And since when did 'fact' become the common term for 'theory'? That's only an issue HERE because someone chose to make it an issue.
EDIT.
From the Urban Dictionary (widely accepted as the best source of the current English common vernacular):
2. In the scientific community, an explanation supported by a evidence and is logically sound.
2. The theory of Evolution logically explains why life is so diverse, and the evidence that supports it includes fossils, DNA, living specimens, and bacterial research.