As far as I know, the Foundation idea came from Miro first and was worked out with the core dev team later. The idea of the foundation was to saveguard Mambo, the devs and the community from false accusations and juridic actions against any of them like the infamous Mr. B. Connoly attempted some months ago.
The idea was good, until Miro pulled the whammy from its sleeves you now so eloquently phrase as "pulling a Miro"; IMHO this will be a phrase that'll go down the history books and might even become the OSM-Mambo jargon for it
Anyway, whenever there's people involved in something, each and every person will have his/her own agenda. That's what your law teacher also tried to teach you. And agenda's can change; overnight even.
So basically no-one can ever give you the guarantee that no-one will ever pull a Miro ever again.
However, the code is protected well enough from people/businesses pulling Miro's by the GPL. This is being demonstrated right now. Miro pulled a Miro and the core-devs forked the code. If part(s) of the core-devs, like the devs from Jamboworks, would pull a Miro, the remainder of the core-devs or other parts of the community can fork OSM-Mambo and continue from there.
This is happening quite a lot in Open Source software projects, not all the time, but more often than you might think...
But I think you shouldn't get too paranoid about jamboworks. The jamboworks devs are all spread around the globe which makes it hard already to keep things together properly as it is. Imagine what would happen if it tried pulling a Miro; chances are it'll fall apart like loose sand. To me jamboworks appears to be nothing more than an opportunistic 'vehicle' to make something out of the hard work the devs are putting into the code. After all, they are the most experienced people related to the code base, so if a large opportunity comes by (e.g. the devshed.com that's also using Mambo, which was implemented for them by the core-devs back then) jamboworks can function as the legal entity representing the core-devs working on such a large-scale project.
Imagine what would happen if jamboworks would pull a Miro; they'd be out of business almost immediately as they'd instantly loose their privileged position which gives jamboworks its edge over others... Miro is a different story in this respect; they always had a commercial version of Mambo and after the latest storm of awards Mambo has won they (or rather: Peter Lamont) smelled money from something they reckon was already theirs.
Most of the devs from Jamboworks are with the core-devs for quite a long time already, but the two most important ones; Andrew Eddie and Emir Sakic, the longest serving on the team, are from different "companies". Andrew is Jamboworks, Emir is sakic.net. They go back a long time and survived many problems Mambo has faced the past years. Besides that, they both have lives and earnings outside Mambo or the OSM.
I wouldn't be too eager to get reassurance no-one would ever pull a Miro again or to seek guarantees because no-one can get you any. And if anyone would give you any, it isn't worth the paper it's written on, since everybody can fork the code at any time.
In Dutch we got a saying: "You shouldn't try to look for ghosts".... In other words: you shouldn't try to look for something that's not there, because right now it is not there; at this moment there's no-one in Jamboworks that's even contemplating pulling a Miro and I'm convinced that no-one in Jamboworks at this very moment even has the notion that Jamboworks could/would pull a Miro in the future. Hence the reaction you experienced to be 'aggressive'. I would be p**ssed too if you'd doubted my good intentions, so are you (judging from you posts; you try to get things out in the open with good intentions, yet you feel 'Judas-ed' when you get 'aggressive' answers), and that's completely human...
Now, to come to a conclusion: The GPL saveguards us all from another Miro. If Jamboworks would pull one, let them. There will plenty of people left to fork the code and continue the work; the community is large enough. Sure, it'll be annoying to say the least and it'll cost some of us (including me) some money, but we'll survive.