As ProFootballTalk.com noted earlier this week, the NFL holds a draft lottery prior to the supplemental draft to determine picking order, much like other pro sports do. Each of the teams that picked in the Top 10 of the 2012 NFL Draft were eligible to win the first pick, with the Bills - who had the tenth pick in April - the least likely to emerge with the pick. Lo and behold, that's precisely what happened.
That means that the Bills had the top pick of each round - which means that they had the first shot at former Baylor wide receiver Josh Gordon, a player they were interested in, each time the league passed on him. The Bills got to pass on Gordon twice before he was picked by the team with the No. 2 overall pick in the supplemental draft, the Cleveland Browns.
Note that the supplemental draft works more like a waiver claim: the Bills would have to have submitted a first- or second-round claim on Gordon to have won his rights over Cleveland. They may very well have submitted a claim in a lower round for Gordon, and would have won had the receiver lasted that long based on their being the top priority team in each round.
Gordon was taken with the second pick in the second round, meaning that the Browns will now part with their second-round pick in next spring's 2013 NFL Draft.
As for the Bills, they'll continue into training camp - set to begin in a fortnight - with enough raw talent and question marks at the wide receiver position to be getting on with.