Why was St. Francis Unsuccessful saving a Soul

Canto XXVII, Line 112ff:  Translation available here (link)

“When I died, Francis came for me.
But one of the black cherubim

Said to him, ‘Hands off this one—don’t wrong me now!

“‘Down he goes among the legions of my slaves
Because he gave fraudulent counsel.
Ever since that moment, I’ve been waiting to snatch him by the hair.

“‘If a guy doesn’t repent, he can’t be pardoned.
And he can’t repent a thing yet still want it.
That’s a contradiction that won’t stand.’

“Oh what a load of sorrow I am! How I came to with a shock
When he grabbed me, saying, ‘Perhaps
You never imagined I’d be versed in logic!’

Guido I da Montefeltro dies and there is a standoff between a demon and a Saint. The Saint loses, and the why of this might give some insight into what inferno really is. Guido was a master at strategy and as such was able to trick others and manipulate events in this world. He was sufficiently repentant to, late in life, join the Franciscan order so that he could work penance for his sins. This was the right move. This is why St. Francis intercedes on his behalf. The demon argues, by contradiction, that not only did Guido willfully sin, but he magnified the sin by planning the sin in advance with the intention to be absolved by it. This, we are told by the demon, does not work. 

St. Francis works to extend mercy to one of his own order. The fault here is not in St. Francis, who is an advocate, but rather in the logic. It seems to me that Guido hung his entire case on logic. I am inferring that Dante here means not only to impugn over-reliance on logic, but that he means to show us once again that the errors of scholasticism are to make too much out of logic, to extend it much further than it should go and by doing so be bound unnecessarily by this framework. Being bound up in rules and logic is Pharisaical. It isn't that the law itself is a problem or that logic itself is a problem, it is making a false authority out of the law. The only authority is God, and one of the lessons of Dante's Comedy is that God's law is about love, not about cold calculating non-contradiction.  

St. Francis might actually be right. The growth of the Franciscans during St. Francis's lifetime (1181-1226) was a divine reaction to the growth of influence of eastern mysticism. St. Francis was influential in bringing the church back to a recognition of its full relationship with nature and spirituality. Francis was canonized two years after his death in 1228, signifying his profound significance to the church in his own time. By contrast, St. Thomas from Aquino (1225-1274) was the master architect of middle scholasticism and brought the Muslim intellectual tradition into the Catholic church through careful integration of Aristotle's thinking.

From Dante's perspective (1265-1321) the influence of Frederick II (1194-1250)  in introducing muslim thought was profound. St. Thomas had recognized that muslim influences on the Christian world were growing because of their advanced academic sophistication and compelling descriptions of the world. It also reintroduce the influence of Greek thinkers more directly and not only as interpreted by earlier Latin writers. St. Thomas transformed this influence into something that could be integrated into the church, although after St. Thomas's death, it took St. Albert the Great to help others see the significance of St. Thomas's work. He was only canonized two years after Dante's death in 1323. 

Guido is being pulled between these forces. I have benefited from Chesterton's great works on St. Francis and St. Thomas as summaries of their lives and influences. It helps me to appreciate the two sides here and the historical context. Humanity needs law to protect from the devil, but we should be careful manipulating law to our advantage. Much like Robert Bolt's great play, A Man for All Seasons, the following scene is given:

MORE: Yes. What would you do? Cut a great road through the law to get after the Devil?

ROPER: I'd cut down every law in England to do that!

MORE: Oh? And when the last law was down, and the Devil turned round on you--where would you hide, Roper, the laws all being flat? This country's planted thick with laws from coast to coast--man's laws, not God's--and if you cut them down--and you're just the man to do it--d'you really think you could stand upright in the winds that would blow then? Yes. I'd give the Devil benefit of law, for my own safety's sake.

So what I am reading into the scene from Canto XXVII is advice about relying too much on prideful sophistication.  This is a sin of pride that least the will to be locked into going with the demon. I am clearly inverting the meaning of Bolt's scene here, but that is because we are talking about God's justice here not man's. The sinner can't appeal to St. Francis because, at root, he doesn't buy into the idea of God's mercy that St. Francis represents. The demon taunts the sinner by using logic. You can't sin knowing you are going to ask for forgiveness because repentance isn't possible. This isn't strictly true. We can learn that we were devilishly manipulated by our own pride. God's love is not limited by our actions, only our own willfulness. What binds the sinner here is an unrelenting insistence on logic that prevents true repentance and the acceptance of mercy. Guido's son Bonconte da Montefeltro is in Purgatory despite being an extreme sinner due to the fact that he does not repeat his father's prideful mistake. 

One final thought: Fraud here is self-deception. Guido's fraud was that he could manipulate the kingdom of God by masterful manipulation of the law. He believed a papal pardon given prior to a sin would have to be upheld. He failed to realize that God is not bound by the law, Jesus said that he fulfills the law through the most extreme act of love, self-sacrifice. Guido was full of pride and vain-glory, and that is why mercy could not reach him at his death.