OpenGLHelpers::isContextActive() strange behaviour on Mac

We just updated a plugin to the latest JUCE develop tip and suddenly run into a strange error. In a function that should never be called from within the OpenGL render callback, we have something like:

    // this method MUST NOT be called from the openGL thread!
    jassert(! OpenGLHelpers::isContextActive());

For some reasons, now suddenly on Mac OS this assertion is triggered when the call obviously comes in from the message thread. Is there a false assumption on our side that only the GL render thread has an active OpenGL context or has something around the implementation of this function on Mac OS has changed recently?