"I leave wok" and "I go home" are both incorrect in your situation. The guy is not English, so it matters little which one he uses. When you leave the office you say: I'm leaving now. I'm going home. I'm knocking off. I'm off.

I am leaving work now DOESNT imply I am going home now ... he/she could be going out for a drink, or meeting friends etc. I am leaving work now, I'll be home in an hour might be a common thing to say.

A native English speaker would say, "I'm leaving work now" or "I'm going home now." You will hear both and both are correct. "I leave work" or "I go home" are only correct as part of a longer sentence when you are talking about habitual actions, such as, "I leave work at five o'clock" or, "I go home on the bus." "Leaving work" is the way English speakers refer to finishing work for the day. They'd say, "I'm leaving my job," if they were talking about giving up and moving to another job.