So I injected the GL_SAMPLES query and the code looks like this:
glBindFramebufferEXT(GL_READ_FRAMEBUFFER_EXT, mFBO);
GLint readSamples;
glGetIntegerv(GL_SAMPLES, &readSamples);
glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER_EXT, currentFramebuffer);
GLint currSamples;
glGetIntegerv(GL_SAMPLES, &currSamples);
glBlitFramebuffer(0, 0, [outTex width], [outTex height], 0, 0, [outTex width], [outTex height], GL_COLOR_BUFFER_BIT, GL_NEAREST);
Apparently the currSamples' value is 0 and the readSamples' is 8. I also checked this on the 10.0.9 and yielded the same values. But what's strange is that why wasn't it throwing an error on the 10.0.9 and it starts to appear now.