There are at least 2 ways to assess this.
1st way
Just treat as a small incident. Only a once-off incident. Nothing to worry about. It would not likely happen again. In Court, just verbally warn or impose a ridiculously small fine; and then let the guy go.
2nd way
Treat this as an extremely serious matter that needs to be nipped in the bud, before it causes more damage to Singapore society and racial harmony. It has been described by others in Stomp that the culprit is a Malay. He was spitting as captured in the video, at a young Chinese lady in public. What does this mean? There are many ramifications. There are many What-Ifs.
2 assumptions - yet to be proven: (a)He is a Malay (b) He is a Malaysian worker on Work Permit in Singapore.
Please note that the culprit was in work clothes/uniform at the end of a work day at the Woodlands bus terminus to catch a bus to where? Yes, to Johore Bahru. You guessed that right. It is possible that the culprit is a Malay from another country, namely Malaysia. Why does he behave this way in Singapore? Obviously he expects to get away with it scot free. That was why the culprit was videoed as saying where is the Police?
Now, what if Singapore lets him go with a slap on the wrist? Will he do it again? Of course. He will be emboldened. Not only him, but many of his fellow Malaysian compatriots will learn that -- hey, we can do this in Singapore and the Courts dare not do anything to us.
Now, what if there were some equally rowdy and violence prone Singaporean Chinese men present, who were family/relatives of the young Chinese girl who was spat on twice? Yes, you guessed right. A violent all-out fight will break out with knives, beer bottles, iron rods, or other assorted weapons. Then when the Malay guy is injured, local Singaporean Malays & Malaysian Malays will protest that the minority race in Singapore is being bullied. This can sour inter-race relations in Singapore. This can damage Singapore-Malaysia relations.
So, in view of the potential risks, I think the best option is to cancel his Work Permit fast - I mean NOW, immediately.
Also issue a total ban against him ever entering Singapore for the next 5 years, after which his permitted entry is subject to review.
The relevant Ministry should call up his employer/company CEO and express deep concern and ire about this matter.
His employer/company should also know what to do after that.
Nothing personal against the culprit - but Singapore as a nation, cannot afford to take this risk. There is too much at stake.