The play in question was clearly a forward pass as defined by current rules, and the Seahawks thus benefited from the lack of an infraction call. This is not seriously in question. The rules governing a lateral, however, should be subject for reassessment in light of current technological realities.
The lateral option exists in order to differentiate from a forward or shovel pass. In the NFL, a lateral when the pitcher is in motion is generally a play-extender as opposed to a play solely in its own right; pro defenses are too fast for most hook-and-ladder plays and direct yardage would otherwise be negative or essentially neutral. In this way, the spirit of the lateral play — on display this past Sunday night — is the same as it was when the game began.
If the play in question had featured a hoofing Charlie Conerly tossing a ball to a trailing Alex Webster in 1955, it would have been a clear lateral to the eyes of all viewers, relative and absolute velocity be damned. Conerly's intent would have been the same as Wilson's. But we don't live in 1955. In that year, Jackie Robinson was tagged out at home by Yogi Berra.
The lateral rule as it exists fails to take into account the reality of a player in motion, and this, as has been stated upthread, is exacerbated by modern replay technology. As few appreciate a baseball manager challenging a stolen base on the pedantic notion that a runner might have left a bag for a microsecond while a tag was applied, rules should be changed to suit the game being played the "right way."
I'll offer this: the majority of all pitcher-in-motion laterals in NFL history have also been "illegal forward passes." What should take precedence for a rules-committee reassessment are these two factors: if the pitch receiver (Davis) was clearly trailing the pitcher (Wilson) when the pitch occurred, and that the pitch itself was not a forward motion.