Hi, I'm Principle Security Engineer at the Open Internet Tools Project. We provide support for developers of counter-surveillance and counter-censorship tools, and along the way spend a fair bit of time talking the the users of these tools in a variety of countries, including folks from Syria. We've absolutely had reports of similar things happening in a number of contexts, including (specifically) Egypt during the revolution. While I do not have a specific source to corroborate this story, it's entirely within the bounds of what I'd expect in both any modern complex war zone with a heavy social media component, and within the norms of what I'd expect in Syria today -- tragically in both cases.
Situations like this are why many folks in these regions will have a number of distinct social media accounts, one of the many reasons why real name and similar policies have a very real cost, and indicative of why operational security in a context like this is both critical and very difficult. Even if you have multiple accounts, making the mistake of leaving your phone logged into the wrong one (or of not keeping straight which account you intend to be expressing which opinions from) can be fatal in a situation like this, and the stress of managing things like this adds to an already terrible environment for psycho-social well-being.