That does appear to be a problem indeed. The LOS rules in this game are different from the board game's and there is an explanation why in this thread tm.asp?m=3103326 - although now many are using the flat map style, it may give credence to revisit the requests for a boardgame LOS model option (please
The computer game does use a different set of LOS rules which are close to the board game rules but not quite exactly the same as that. However, I'm a little surprised that the new LOS system doesn't prohibit that shot, and I am wondering whether Partisans is using an old LOS data file somehow. I will take a look at it and see whether this is the case.