How To Open A Push/Pull Door Without Looking Stupid
In this situation you're basically playing Russian Roulette with your dignity. Everyone's standing around on the street watching to see what you do. In this situation the best thing to do is to push first. Push lightly enough so that it's not obvious you're pushing with the intent to open the door. Then if you feel it start to give way, keep going, it's a pusher. If you feel resistance, that's your cue to begin pulling. Hopefully if you've executed this technique properly no one's the wiser to your internal dilemma.
That is a far better strategy than going in too confident assuming it's a pull. That's when you really look stupid because if your first pull isn't right on the money you might think the door is heavy and you didn't give it enough power so you pull again. Then by that time people are laughing and you feel stupid so you get stubborn and try to rip the door off the hinges, in the process breaking the glass and urinating on yourself. At that point you've crossed the line and should leave immediately because the hostess inside is calling 9-1-1.