I'm not sure why the NFL would fine them $20,000 for not doing anything not banned by the league
http://www.utsandiego.com/news/2012/oct/22/chargers-dont-expect-cheating-accusations-stick/
Apparently they were using a special towel to treat the balls so they would be easier to hold in inclement weather
This obviously was used to help both the QB and the WRs
No label of "cheater" was ever applied because - well because they lost and they're the Chargers and no threat to anybody
In the Patriots case the mere allegation with no proof has renewed the misapplied "cheater" label in which a 2007 violation of a new 2006 rule is somehow interpreted by jealous fans as invalidating only the Super Bowls of the Patriots, regardless of how many teams engaged in sideline taping while it was allowed under the rules