Numerous sources, including wikipedia, say he ran the NY Marathon in 1999.
I checked the NY Marathon's website to verify this and I found a David Paterson of NY did run the marathon in 6:06:00 in 1999.
This runner missed the mats at:
5k, 10k, 15k, 20k, the half, 25k, 30k, 20m, 35k and 40k.
Something is VERY fishy about this.