The announcers said it has happened to the Bills a couple other times this season. Plus when it happened, the refs gave the Bills a bone by reviewing the first down play. The Bills pretty much got a free time-out.
The imminent snap rule only applies when the extra player is in formation not when he is on his way off the field http://static.nfl.com/static/conten...fs/8_2013_Players_Subs_Equip_GeneralRules.pdf
LOL....that franchise is such a mess... You go from being the declared starter for the rest of the season to 3rd stringer...