Near misses is something that is really only opinion and speculation (because it didn't happen), and would be difficult to prove (I would imagine). However, what is certain, is that they awarded an FA Cup semi final to a stadium that didn't have a current safety certificate. That, to me, is certainly worthy of investigation.
Near miss is certainly not opinion or speculation, it is recognisable and you have a duty to report it if you work in the emergency services, event organisers etc.
The whole idea is for everyone to be made aware of the circumstances of what happened and why it could have lead to disaster. The point being if you are a large institution like the FA responsible for 50,000 people at an event you certainly don't encourage a culture of 'we got away with that one'
Hillsborough was like other disasters, they are a chain of critical events. If you have predicted the problems in advance you only have to remove one event to avoid the disaster. Just a few I can think of would be
Look at and learn from previous Disasters at football ground
Look at and learn from near misses at Hillsborough
Choice of suitable stadium in the first place
Fences around the pitch that could not be easily opened
Pens that could not be easily opened
Poor ticket distribution by the FA
The problems of playing at a neutral ground. In effect the police have 50,000 away fans arriving
Poor pre planning. The previous year fans could not get near the turnstiles without a ticket.
Wrong person in charge. Lack of experience (first game was a cup semi) knowledge, training, or guidance from other staff.
Gate to the Tunnel was not closed when the middle pens were already full.
Communication equipment was poor or non existent. Had everyone known the gates were about to be open, it would have taken just one member of staff/police to realise the tunnel gate must be closed first.
The Major Incident procedure was totally ineffective. Clearly that had never done a combined exercise with all the emergency services.
That said for us fans in the 80's we were treated with utter contempt by the authorities and a lot of the police. Yes we were no angels and we all played our part in the lead up to Hillsborough. In some way or another we are all responsible for those 96 deaths.
Of course its much more convenient to find a scape goat like Dukenfield. He was faced with a critical situation around the turnstiles at ten to three. With reports of the wall about to collapse and people already being crushed.
How many of us can honestly say we would not have opened the gates, faced with that situation. A decision that must have been agreed or advised by his immediate staff.
Yes Duckenfield lied at first and then there was a conspiracy by many high ranking police officers and that's what they should be prosecuted for.
Whether David Dukenfield should be the one facing a manslaughter charge is of course debatable.