The so-called Peter could not have declared, seen or understood supernatural stuff which never happened.The simpler way to explain why essentially "Mark" treated Peter (& disciples) as a hostile witness is because, for a variety of reasons (most invented by the author), Peter did not declare, see or understand the extraordinary, supernatural stuff which support the Christian faith....
gMark is not history but propaganda against the Jews to explain the Fall of the Jewish Temple c 70 CE.
The story of gMark is that God sent his Son to the Jews but he was rejected and killed by them and abandoned by his handpicked disciples and Peter who denied even knowing Jesus.
The parable in Mark 12.1-11 represents the propaganda of gMark
1 And he began to speak unto them by parables. A certain man planted a vineyard, and set an hedge about it, and digged a place for the winefat, and built a tower, and let it out to husbandmen, and went into a far country.
2 And at the season he sent to the husbandmen a servant, that he might receive from the husbandmen of the fruit of the vineyard.
3 And they caught him, and beat him, and sent him away empty.
4 And again he sent unto them another servant; and at him they cast stones, and wounded him in the head, and sent him away shamefully handled.
5 And again he sent another; and him they killed, and many others; beating some, and killing some.
6 Having yet therefore one son, his wellbeloved, he sent him also last unto them, saying, They will reverence my son.
7 But those husbandmen said among themselves, This is the heir; come, let us kill him, and the inheritance shall be ours.'
8 And they took him, and killed him, and cast him out of the vineyard.
9 What shall therefore the lord of the vineyard do? he will come and destroy the husbandmen, and will give the vineyard unto others.
10 And have ye not read this scripture; The stone which the builders rejected is become the head of the corner
11 This was the Lord's doing, and it is marvellous in our eyes?
The words of the Lord in the books of the Prophets were fulfilled-- the Jews killed the Son of God so Jerusalem, the Jewish Temple were destroyed and non-Jews accepted the story of Jesus as the son of God.
But when ye shall see the abomination of desolation, spoken of by Daniel the prophet, standing where it ought not, (let him that readeth understand,) then let them that be in Judaea flee to the mountains.