Firstly: 

The fuqaha’ differed concerning the threefold divorce (talaaq). The correct view is that it counts as one divorce, whether it is uttered in a single phrase, such as saying “You are thrice divorced” or in repeated words such as saying, “You are divorced, you are divorced, you are divorced.” This is the view favoured by Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) and was the view regarded as most correct by Shaykh al-Sa’di (may Allaah have mercy on him) and Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him). 

They quoted as evidence the hadeeth narrated by Muslim (1472) from Ibn ‘Abbaas (may Allaah be pleased with him) who said: At the time of the Messenger of Allaah (peace and blessings of Allaah be upon him), Abu Bakr and the first two years of ‘Umar’s caliphate, a threefold divorce was counted as one. Then ‘Umar ibn al-Khattaab said: People have become hasty in a matter in which they should take their time. I am thinking of holding them to it. So he made it binding upon them. 

Secondly: 

If a man divorces his wife in anger, one of three scenarios must apply: 

1-His anger was mild and did not affect his will and choice, so his divorce is valid and counts as such.

2-His anger was so intense that he did not know or realize what he was saying. This divorce does not count as such because in this case he was like an insane person who is not to be brought to account for what he says.

With regard to these two scenarios of anger, there is no difference of opinion among the scholars on the ruling. There remains the third scenario which is: 

3-Intense anger which affects a person’s will and makes him speak words as if he is compelled to do so, but he soon regrets it as soon as his anger dissipates; but the anger does not reach the stage where he does not feel or realize what he is saying and cannot control his words or actions. The scholars differed concerning the ruling on this type of anger. The more correct view – as Shaykh Ibn Baaz (may Allaah have mercy on him) said – is that it does not count as such either, because the Prophet (peace and blessings of Allaah be upon him) said: “There is no divorce and no manumission at the time of coercion.” Narrated by Ibn Majaah (2047); classed as saheeh by al-Albaani in al-Irwa’ (2047). Coercion here was interpreted by the scholars as referring to compulsion and intense anger.

This view was favoured by Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) and his student Ibn al-Qayyim who wrote a well known essay concerning that entitled Ighaathat al-Lahfaan fi Hukm Talaaq al-Ghadbaan. 

See the answer to question no. 45174. 

Based on this opinion, if your friend spoke the word of divorce at a moment of intense anger, then no divorce has taken place; if he was slightly angry, then it counts as one divorce. 

And Allaah knows best.