[Bette]

An embarrassed Osi Umenyiora (FSY) said he overreacted when he walked out of practice on Monday — and he's paying for it.
The two-time Pro Bowl defensive end with the New York Giants acknowledged he had a minor tiff with his new defensive coordinator, but said his decision to skip practice was probably the worst thing he has done in his NFL career.
Umenyiora on Tuesday declined to disclose the nature of his disagreement with coordinator Bill Sheridan, saying only the issue that set him off was 'minuscule' and never should have escalated.
The Giants fined Umenyiora an undisclosed amount of money that the player said would feed a lot of people in undeveloped countries

Giants' Umenyiora: Going AWOL 'a very bad moral decision' - USATODAY.com

Osi admits this was a stupid thing to do. Teammates had wanted posters taped up with a $1 million dollar reward for his return. They wont let him forget it.
I dont think this is a sign of character weakness. Just something that got a little out of hand. Osi says it wasnt over anything important.