I think this plugin should be added. It has the options to set for only certain groups can use it and what not. It's also made by staff at MyBBCentral too if that will matter. But yes this should be added as it would be very interesting.
That plug-in is a private plug-in made by omni. Although the Idea is great unfortunately Philly cannot use it and would need to code it himself. Even then it would be similar to HF and could cause issues. Although Philly likes the idea it just simply is not feasible.
In regards to the post at hand, Although this seems like a great idea what use would it be to anyone on the forum? Why would I need to see what someone reported. To be honest I think it would be used more as a flaming tool then a useful one. Ex; 'OMG you reported someone not having proof you snitch'. I think reporting posts needs to stay private in order for the system to be successful. Already as it is there are not many people reporting posts and I believe everyone on FK needs to step up to the plate in that regard.