Hyam Maccoby is obviously correct to state that Judas never "betrayed" Jesus. This view is eminently defensible from the New Testament itself.
1) Jesus obviously had foreknowledge that Judas was going to inform the authorities where to find him. First of all, if we assume that as the Son of God and the Second member of the Holy Trinity, Jesus is God and therefore knows everything, OF COURSE he then must know what Judas is up to.
2) The Gospels themselves say that Jesus knew. In Matthew, when Judas kisses Jesus and asks, "Is it I?" Jesus tells him, "Go, do what you must."
3) It is therefore logical to suppose that Jesus actually SENT Judas to inform the authorities. Think about it. They've just had the Last Supper. This is Jerusalem in the 1st Century; not a lot of night life. After dining on a holiday, there was nothing else to do but go to bed inside the city, more or less where they had supper. But instead, Jesus and the disciples leave the city and go to the Mount of Olives. Question: How would the authorities know to look for Jesus there? For surely, Jesus WANTED the authorities to find him. Either in his capacity as the sacrificial Lamb of God, knowing he's going to be arrested, tried, and crucified, wanting to go through with it because of his love of mankind, or in his capacity as Messiah, wanting to battle with the Romans in order to usher in the Age of the Messiah -- either way, he can't get it going unless he confronts the authorities, and he can't do that if they don't know where to find him. So OF COURSE he needs someone to TELL them -- and that someone is Judas.
4) Now consider who Judas really is. He's the only disciple with a "surname." But the "surname is no surname; it's a STREET name. It's like being named "Mack the Knife."
What does it mean? "Is" - "Ish," Hebrew/Aramaic for "man." And "S-cariot" is a blend of Latin and Hebrew. In Latin, a "sicarius" means "dagger." (It is from this word that we get the words "cigar" and "cigar-ette' ('little cigar') since both have the general shape of a dagger.) And in Hebrew, the "iot" ending is used with plural feminine nouns, so "sicarius" the dagger becomes "sicar-iot" the daggers.
Judas Iscariot then is "Judas the Daggerman," or "Judas, Man of Daggers."
5) This is significant because Josephus records that during this time, there was a group of assassins within the party of the Zealots who frequently picked off stray Romans by stabbing them to death -- with sicarii! In fact, that's what they were called -- The Sicarii.
Judas was in this class of Jewish patriot.
6) So how could it possibly be that THIS Judas, of ALL people, could possibly have turned over his beloved master to the very people he hated the most?
The answer must be he didn't know what he was doing.
Jesus sends him to tell the authorities where to find him. Judas gladly does so, because he thinks the Messianic Revolt as foretold by Zechariah and Joel is going to occur this very evening. He PRETENDS to the authorities to be a turncoat in order to embellish the verisimilitude; this is why he accepts their payments of 30 pieces of silver.
He leads the authorities to Jesus, but to his shock, horror, and dismay, instead of ushering in the Age of the Messiah, Jesus is meekly arrested, and the whimper of te revolution is over before it truly began.
Judas knew what would happen next -- Jesus was going to be executed, probably on the cross.
In great despair, he throws back the pieces of silver, and then hangs himself in grief.
The suicide is the key to the story. If Judas had truly and cravenly "betrayed" Jesus, then why the waterworks afterward? Why the grief and despair?
But if Judas didn't know what was going to happen, then all is clear and understandable. He killed himself because it went terribly wrong, and he felt horrible guilt about his unwitting role.
I go into this and more in my booklet, "A Scientific Determination of the Exact Time and Date of the Death of Jesus of Nazareth." Please go to www.romaband.com/james for more details.