ORCHARD PARK, N.Y. -- Chris Johnson sat at his locker contemplating the Raiders' unfathomable 38-35 loss to the Buffalo Bills on Sunday and pointed the finger squarely at himself.

The Raiders were looking for someone to stop an avalanche of offense unleashed by the Bills in the second half at Ralph Wilson Stadium. With the Raiders leading 35-31, and 32 seconds remaining, Buffalo quarterback Ryan Fitzpatrick threw to Donald Jones in the left corner of the end zone.

Johnson had good coverage, and for an instant the game was in his hands. He dropped it.

"That's what's so heartbreaking, man," Johnson said. "I get that pick, and it's game over."

Two plays later, Fitzpatrick found David Nelson wide open in the middle of the end zone without an Oakland defender in sight for what turned out to be the winning points with 14 seconds to play.

Had Johnson held on, none of the melodrama that played out over the next several minutes would have been necessary, although he wasn't the only guilty party on defense.

The game ended with Jason Campbell throwing a jump ball from the Oakland 44 all the way into the end zone, and Da'Norris Searcy wresting the ball away from rookie Denarius Moore as time expired.

While officials sorted out what they later said was an inadvertent replay buzzer, a few Raiders thought they might escape with a win and a 2-0 record.

Instead, referee Mike Carey announced the interception stood. The Bills were 2-0, and the Raiders were left to spend their cross-country charter flight pondering one of the worst defensive collapses in franchise history, knowing they have back-to-back home games against the New York Jets and New England Patriots up next.

"We didn't get them stopped," Raiders coach Hue Jackson said. "We've got to find a way to finish the game. We did not finish. We had an opportunity and let it slip through our hands."

Trailing 21-3 at halftime, Buffalo had five possessions in the second half and scored touchdowns on all five, the first time that's happened in the NFL since 1993.

Over the final 30 minutes, the Bills had 25 first downs and 326 yards of total offense. Fitzpatrick completed 17 of 26 passes for 162 yards and three touchdowns, and the Bills rushed for 164 of their 217 yards on the ground, with Fred Jackson finishing with 117 yards on 15 carries.

There was some postgame grumbling about the officiating. Buffalo got five first downs on Oakland penalties, with the Raiders getting flagged six times for 65 yards in the second half.

Yet with Campbell completing 23 of 33 passes for 323 yards and two touchdowns, Moore catching five passes for 146 yards -- including a spectacular leaping 50-yard touchdown reception -- and the Raiders rolling up 454 yards of offense and 26 first downs, the inability of Oakland's defense to get off the field was the overriding issue.

Two times in the fourth quarter the Raiders defense gave up the lead, and the offense immediately took it back. With the Raiders down 24-21, Campbell capped an 80-yard drive with a 12-yard swing pass to Darren McFadden. With Buffalo up 31-28, Campbell unleashed his 50-yard strike to Moore with 3:41 left.

Both times Oakland couldn't come through on defense, and it wasn't just the dropped interception by Johnson. Mistakes were everywhere.

"We didn't seem to give the offense any help in the second half," defensive tackle Richard Seymour said. "They were getting the ball out quick, quick routes, a lot of timing stuff. It isn't good enough, period."

On the winning touchdown pass, both middle linebacker Rolando McClain and linebacker Kamerion Wimbley appeared to go with Buffalo running back C.J. Spiller, while Nelson, in the left slot, broke into a wide-open middle. Jackson and the players were nonspecific about the responsibilities on that decisive play.

"Blown coverage, plain and simple," Jackson said.

Said Fitzpatrick: "I don't know what happened, but I think they misaligned to be honest."

Defensive tackle Tommy Kelly was peeved because Fitzpatrick did everything the Raiders expected, and they still couldn't stop him.

"We knew what they were going to do -- spread us out, try to throw those little crossing routes," Kelly said. "Just get the man on the ground. And we just didn't do it as a defense for some reason. I don't know why. But we've got a six-hour flight to figure out what the hell happened."