AFAIK a jailbreak is not possible in a couple of minutes. I don't know if you mentioned how long your so-called friend was using the phone but no matter which approach one chooses it requires rebooting the phone etc.
As far as I remember you haven't mentioned which version of iOS you were running the "past weekend" but a jailbreak might not even be possible for that specific iOS iteration atm.
I know that law enforcement have software they use to access and download info off of phones.
Law Enforcement had huge issues/wasn't able to read out data from an iPhone in that case we all know of. Also, this isn't related at all to what happened to you unless your "friend" is working for Homeland Security, NSA, FBI or whatever or "payed an Israeli firm" beforehand in order to get hold of your personal data.
Maybe you're the boss of a multinational conglomerate or a high profile politician in the end. Who knows?
Well, maybe not otherwise you'd have access to much better resources than the macrumors forums to resolve this mysterious case.
Maybe you were witness to a supernatural incident? I totally believe in science so I'd rule that out.
Personally - but that is really my opinion - Apple Inc. is one of the companies I'd trust more than others when it comes to keeping my personal data safe - relatively. If it's digital it's very possibly not a 100% safe.
I am sure that there is absolutely no way to install an iOS app from the App Store that is able to spy out your phone. Apple would have long banned this from the Store respectively haven't I read any articles recently about a huge security scandal regarding an iOS app. Each app is more or less reviewed by them before it gets a pass anyways.
What's to gain? People keep alot of personal financial info on their phones now.
So, you're saying YOU keep a lot of financial info on YOUR phone? Don't do it then (in form of emails, messages etc.). Credit Card data is blocked behind your password/code in the appropriate settings. You'll need to enter your pass code/use touchID once more to access this data. There would be easier analogue ways to get hold of that too.
Ah well, at least this thread was good entertainment for me while having a
very slow office hour. I'd say you're being a bit paranoid or at least trying
really hard to prove that there
must have been some kind of malpractice. I dunno.
But again: thanks for the
great entertainment.