Reflow soldering, pin longer than pad?
Probably not a big deal, since that portion of the pin looks to actually be rounded and not square, which is hard to see in the picture below:

Source: https://uk.rs-online.com/web/p/fpc-connectors/7883521/
The dimensions in the datasheet don't show the rounded inside of the connectors which would make it easier to solder and align itself on the pads. I don't know that I'd even worry about if the quantities of the board were low (like 100 or less).