Also the scaling - in this case the original had reasonable scaling but it can be manipulated. The changes could be small enough to be random fluctuations on on

Also the scaling - in this case the original had reasonable scaling but it can be manipulated. The changes could be small enough to be random fluctuations on one series and so no real match. However the graph does show that a slightly deeper look would be worthwhile - even if it is a very quick one to see that the data is manipulated e.g. climate deniers graphs of temperature all starting on the same year. If you change the starting year you got rather different results.