Where have I said that?
My rather trivial point was that, without being able to read the bottom line of the flag, it's impossible to know for sure if it's for Jabhat al-Nusta - it could be the generic jihadi flag without specifying a particular group (often seen in London at al-Muhajirun or Hizb ut-Tahrir rallies for example) or they could in theory be supporting other jihadi luminaries such as Jund al-Aqsa, the Pakistani Taliban, or the Caucasus Emirate, or any other of the dozen or so jihadi groups who use this particular flag (obviously very unlikely given the context, and irrelevant in regards to the problem):
Pretty sure I can make out 'Jabhat al-Nusra' on the lower flag in the second pic here, although it's extremely unclear (edit: am I imagining it?), but the other flags clearly don't specify Nusra under either moniker.
It would be interesting (and maybe legally relevant?) to know if flags specifically saying 'Jabhat al-Nusra' or 'Jabhat Fatah al-Sham' were flown at these protests.