A lot of institutions have a policy of using 'allegedly' for anyone accused of a crime before they've been convicted. It protects the speaker from libel.

People may very break with this policy, but I didn't see evidence of that at the site which was linked.

A lot of institutions have a policy of using 'allegedly' for anyone accused of a crime...

I wasn't aware Obama, during speeches, was classified an "institution." Nor was I aware, as you say, the the President of the US was in significant danger of a libel suit if he misspoke on any given issue. Yet these are the assumptions upon which your statement, given the context, seems necessarily predicated. Do you have any supporting evidence?

It seems to me that President Obama is speaking here (in both cases) as an individual, not an "institution." It seems to me that in the US, unlike the UK, we don't have significant fears of libel suits. I believe that the US President would have even less fear of such than most individuals. It seems to me that even if he did, and all you propose above is true, he would be similarly foolhardy instantly calling one institution (and one individual, in particular) "stupid", before the facts were known, while carefully deploying the word "allegedly" in another case.

It seems to me this juxtaposition tells us something about what he wants to see as true, and what he is, in contrast, very cautious about.

Perhaps I'm off my rocker for making so many far-out assumptions. So be it! :-)