The same as any other student from any normal school would get, which is not consistent depending on the school admin. The school should have some room to decide, instead of just following blindly what the public feels. It is after all, an institution with some individuality and if the school admin doesn't have the balls to stick to its own guns then they should be sacked.
There are so many courses of actions; counselling, etc. You have to remember that whatever the case, he may not be that young, but he is still young. If you had made a mistake when you were younger I'm sure you'd have wanted some leniency too. Even if you didn't care, your parents would.
There is no reason for any institution to simply bend to the will of the public. Do you think he is the only one doing such things? Perhaps he is the first to punch, but I'm pretty sure there have been near-violent acts as well, brandishing of the middle finger is so commonplace nowadays that when I see it on the streets I don't even find it out of place already.
You can say, no, they did not use any force.. But isn't that akin to 五十步笑一百步？ (Wonder if that's the correct phrase, my Chinese isn't that good)
Every parents would feel proud to have their kids studying at one of Singapore's top institution. Now that kid has disappoint and deeply hurt and shamed his parents. The poor father must be wondering what has he done to have that kind of son.....