I haven't played the patch so I don't know if there is a single routine that is allowing this to happen. If it is a single routine repeated every time (like the near post flick on in 07 or the lurking long shot in 06) then yes it is a flaw in the match engine.
But if it is realism you are after then you do have the option to not exploit this flaw.
If it were repeatedly successful against the same teams because of deficiencies in those teams thus making it reflective of a real life team lacking in a manager capable of organising defensively for set pieces or lacking in the players with the abilities to deal with that routine, then I would accept it as realistic. But if works repeatedly against every team independent of those two factors then it is an unrealistic flaw in the engine.
Basically it comes down to your FM philosophy:-
1. Treat it as a game where I want to win and flaws are there to be exploited => use the corner routine that bags you 20+ goals a season
2. Treat it as a simulation thus consciously set up tactics so as not to exploit flaws that do not reflect ones which are explainable in real life terms => don't use the corner routine that bags you 20+ goals a season
I'm not saying the same philosophy can be applied to realistic implementations that appear to create difficulties in the match engine (Targetmen in FM 07, lone strikers and AMCs in pre patch FM 08). In this thread the issue is corners and in my opinion if you decide not to exploit the flaws you probably would get more realistic statistics. Of course the foundations of your FM ethics will get tested whenever the AI happens to score from the same exploit. Whether or not you retaliate is up to you