Mistakes of A Sahaba

There are many examples where the sahaba made mistakes during their lifetime. However, the Ahle Sunnah Wal Jamaat do not believe in the infallibility of the sahaba. Since the sahaba made mistakes does this mean we should stop following them ? The correct answer to this question is the sahaba should be only followed when they are correct. For example Abi Bakr (ra) himself is believed to have said "Follow me until I lead you on the path of Allah." He said: "Help me, if I be the right; set me right, if I be the wrong. The weak among you shall be strong to me until his rights have been vindicated. The strong among you shall be weak with me until, if God wills, I have taken what is due to him. Obey me as long as I obey Allah and His Prophet; when I disobey Him and his Prophet, obey me not.""
Therefore, when a sahaba commits a mistake it is not compulsory for us to follow him. Now when one debates against the shia they point out these mistakes of the sahaba and force a sunni to curse them. For example in Tijani's book "Then I Guided" he cites a quote where Umar (ra) gives an incorrect rule regarding Tayamum. He cites from Bukhari:
Al-Bukhari stated in his book, in a chapter which deals with ritual impurity: I heard Shaqiq ibn Salmah saying: I was with Abdullah and Abu Musa, and Abu Musa asked, "What do you say about a man who is unclean but cannot find water?" Abdullah answered, "He should not pray until he finds water." Abu Musa then asked, "What do you think about what the Prophet said to Ammar [regarding the issue of impurity] when Ammar asked him?" Abdullah said, "For that reason Umar was not satisfied with [that]." Abu Musa said, "Forget about what Ammar said, but what do you say about the Qur'anic verse?" Abdullah did not know what to say, but he justified his stance by saying, "If we let them do that, then whenever the water becomes cold, they avoid using it to clean themselves, and instead they use sand. I said to Shaqiq, "Abdullah is most certainly hated for that." He said, "Yes".
Sahih, Bukhari, vol 1 p 54

Over here it is clear that Umar (ra) made a mistake. However, does this mean accepting the shia sect will make a prevent a person from making mistakes or committing sins? Are the scholars which the 12rs follow also not capable of making mistakes ? Are they infallible ?

Below is a pictures of Al Tijani where he is using his left hand to drink coffee.




It is reported in Suyuti book regarding the Calipate Imam Hassan ibn Ali (as), that Imam Hassan (as) gave a ruling in fiqh to only use one's left hand when dealing with impure acts such as cleaning the nose, or any other form of cleansing.

In fact, Marwan bin Hakam used to abuse to Imam Hassan (as) on many occasions, and the only time Imam Hassan (as) reprimanded him was when he saw that Marwaan using his right hand to clean his nose.

Ibn Saád reports from Zurayq ibn Suwār: Marwān and al-Ĥasan had an argument. and Marwān began to speak rough; al-Ĥasan kept silent. And then Marwān began picking his nose with his right hand. Al-Ĥasan said: 'Woe unto you. Do you not know to use the right hand for clean things, and the left for the unclean? Shame on you.' This silenced Marwān. (Tareek e Khulufa, Suyuti)



Anyway, this is just example. On top of that there are examples when there were mistakes by Imam Khomeini when he took a temporal position to rule over Iran. I'm still in process of researching the details of those events. However, my purpose of this research is not ask shias or sunnis to curse Imam Khomeini, but it is point out that we are all human who don't have a status to be infallible. If shias think I am impressed by the way they quote our sunni sources to prove the mistakes of the sahaba, they are wrong. In fact, I have seen fiqhi mistakes made by the 12r marja too made big mistakes. So in this case who are we suppose to follow ? We are only suppose to follow our fallible leadership when their teachings are parallel to Quran, Sunnah and the Ahlul Bayt.

May Allah Forgive us for our Sins which we commit day and night !