yeah, but that was 10 years ago, since when Love Parade have been involved in organising major largescale events in several countries as well as Germany, and this really is very basic level crowd management stuff that in essence is taught even to volunteer stewards on the glastonbury steward training courses.
If they didn't have a contingency plan for this eventuality in their risk assessment / event manul / crowd safety policy, or if they then ignored this policy, or the policy was flawed and was followed resulting in this terrible situation then the person in charge of crowd safety for Love Parade is likely to rightly be spending a long time in prison, possibly joined by the board (depending upon germany's manslaughter / corporate manslaughter).
As someone who's been the person with ultimate responsibility / liability for crowd safety at reasonably largescale events (not quite to this scale, but not that far off on occasion), I just can't believe that someone specialising in such activities would have made such a fundamental error at least at the planning stages. This combined with my personal experience of the reaction some inexperienced police forces can have when confronted with a situation such as this - ie ignore everything in the event manual, don't consult with event control, and just intervene as they see fit - plus the press reports stating that the police closed off the entrance, leads me to my initial conclusion that it's likely IMO that while the Love Parade should obviously have been more on top of the situation, it seems likely that the police ultimately took the action that caused a bad situation to turn deadly.
I may be proved wrong, but given that it's a situation where on one side there's a specialist events organisation with over 20 years experience of running events of this scale and nature vs a police in a relatively small provincial city which is likely to have virtually no comparable experience to draw on, and one of them has panicked and made such a tragic basic error, I know where I'd be looking first if I was conducting a truly independent enquiry rather than a whitewash / coverup of police incompetence / negligence.
essentially IMO its going to boil down to who gave the order to close the entry point, and who was responsible for enacting that order in the incompetent manor that it was done in, combined with whether they followed agreed procedures for such an eventuality or not.