被人不斷用粗口問候更把我手臂"渣魚",事隔一天我打了佢4下

i suggest you should refer your case to professional lawyer.

If you refer the case to Hong Kong police Force, I would say that it is highly possible for both of you to be charged with the crime 'Fighting in Public Places'. According to the Hong Kong Law Chapter 245, Public Order Ordinance, Section 25,Any person who takes part in an unlawful fight in a public place shall be guilty of an offence and shall be liable on summary conviction to a fine of $5000 and to imprisonment for 12 months.

Based on your background, you may have a heavier legal liability.

Besides, you should deny his father's remedial request. Remedial practice shall only be incurred if there is an unilateral legal liability or unilateral mistake. From your description, both of you hold the legal liability to the issue. Hence, you shall deny the remedial request and turn to professional lawyer. I guess your legal representative will help you lessen your legal liability by saying that you are under provocation.

I hope the above help you out a bit.

2012-05-08 17:53:35 補充：
Hong Kong Law Chapter 212 Section 8 is not applicable in your case as you are not killing someone by misfortune.

Hong Kong Law Chapter 220 Section 101A is not applicable in your case as you are not exercising your civil rights to 'arrest' someone.

法律係有比市民自衛既權利 但係如果人地打左你一拳你就停手 你就不可以打番佢，因為咁樣就係報復而非自衛了。

下面是一些相關法律條文：

香港法例第212章8條
任何人因不幸情況或出於自衞而殺人，或在任何其他情況下合法殺人，均不會因此招致處罰。

香港法例第220章101A條
(1) 任何人於防止罪案時或於進行或協助合法逮捕罪犯或疑犯或非法地不在羈留中的人時，可使用就當時環境而言屬於合理的武力。

你錯在郁佢先

如果佢郁你先 你再打佢 都可以話係自衛

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