Ok, so a 235 seater has 50 non-refundable tickets and 25 of these are no shows. The Airline then sells the 25 "empty" seats to stand-by passengers, would this make this LF 106%
Yes in revenue terms, however in actual passengers on board it is obviously 100%.
Institutional carriers such as BA, LH, AF etc. often oversell flights as they expect passengers to not turn up.
Remember, the way on this site we use load factor to calculate passenger demand. This is obviously very inaccurate considering all routes have different price elasticity of demand (e.g. LHR-JFK is very much closer to 0 than BLK-ALC)
Load factor is very irrelevant now in such a competitive market.