I'll take issue with the 'expert' here. Firstly the threat was (supposed to be) to cut off BOTH INDEX AND MIDDLE FINGER of the English Longbow Archers - hence the two fingered salute (back of hand outwards) that is an insulting gesture in the UK.
Secondly the 'witnesses'....
"The lack of reliable and consistent sources makes it very difficult to accurately estimate the numbers on both sides."
Thirdly:
The sign also pre-dates Agincourt and the story is that the English and Welsh archers gave the salute to the fleeing French reserve when then saw their comrades defeated.
"The "two-fingers salute" is certainly older than Agincourt. It appears in the Macclesfield Psalter MS 1-2005 Fitzwilliam Museum, Cambridge, believed to be produced in about 1330, Folio 130 Recto, CDROM p261, being made by a glove on the extended nose of a marginalia depicting a human headed hybrid beast, ridden by a person playing the pipe and tabor. The Psalter marginalia have many absurdities and obscenities so the traditional meaning of this gesture would not be out of place here. As the gesture is made by a disembodied glove accidental positioning of the hand may be ruled out."
As for Chivalry and ransoming prisoners,
"The only French success was a sally from Agincourt Castle behind the lines attacking the unprotected English baggage train. Ysambart D'Agincourt with 1,000 peasants seized the King's personal belongings and killed the unarmed attendants and 'page boys' usually little children. Thinking his rear was under attack and worried that the prisoners would rearm themselves with the weapons strewn upon the field, Henry ordered the slaughter of his French prisoners. The nobles and senior officers, wishing to ransom the captives (and perhaps from a sense of honour, having received the surrender ['passeport'] of the prisoners), refused. The task fell to the common soldiers."
It's like all historical events , scientific reports etc etc, it depends on who commissions the research. A few years ago we had 'The REAL story' of the Spnaish Armarda. It was claimed that the vast majority of English people wanted the Spanish to win and would have rebelled if they had made landfall. They also claimed that it was the weather that defeated them and nothing to do with the way the English fought. The series was paid for by - yup - The Sanish government and Catholic church !
Bit like the cigarette makers telling me that smoking is good for me !
It's like the stories detracting from the US Marines taking of the castle at Chapultepec (and hence their 'hymn' From the Halls of Montezuma)by belittling their achievement because it was manned by a couple of hundred Mexican cadets. Does it matter ?
THEY WON ! and with a lot less than the 5 - 1 supposed ratio of dislodging dug in troops, and it WAS A CASTLE - PURPOSE BUILT TO DEFEND !
Info sources:
http://en.wikipedia.org/wiki/Battle_of_Agincourthttp://en.wikipedia.org/wiki/Battle_of_ChapultepecWe were wrong to bomb Dresden - but it was OK for the Germans to bomb Coventry, You were wrong to use atomic weapons on Japan, the US never went to the moon, The Holocaust didn't happen, Lady Di was murdered, The queen is a lizard.... Ok I'll give them that one

DOES IT MATTER ?