One of the reasons the record stood for so long was that there has to be a perfect situation for the attempt to even occur. The line of scrimmage has to be around the 46 yard line. Depending on the kicker, most teams would rather just chuck up a hail Mary from that spot than try a FG. Most of the attempts of 63+ took place at the end of the first half, just as this one did, where there's not as much of a sense of urgency. At that point your choices are FG try, hail mary or take a knee.
Jason Elam was the Broncos' kicker for many years. He had a strong enough leg & the Denver air, and in fact he was one of the 3 kickers who had tied the record. Janikowski has always had the leg no matter where, and the Raiders suck just hard enough for it to have happened.
There is a little known clause to the fair-catch rule, where the team making a fair-catch is allowed a free kick with no defense. Basically allowing the kicker to take a running kick-off style kick at the goalposts. This is the scenario I saw having the best chance of breaking the record.
There have only been ~30 attempts of 63 or more yards since 1988. Multiple attempts by Elam & Janikoswki[DOUBLEPOST=1386634455,1386634341][/DOUBLEPOST]
[DOUBLEPOST=1386634611][/DOUBLEPOST]5 of those attaempts were in Denver. All unless noted were at the end of the first half.