Why did Yakov see fit to mention the fact that 'the G-d of his father was with him'?
Rashbam and Seforno: He meant to say that, in spite of Lavan's accusations that he had stolen his sheep, everything that he owned was what Hashem had given him, and that he had stolen nothing from Lavan.
Ohr ha'Chayim: Do not say that Lavan is understandably upset, for your flock is much greater than his. This was a Brachah from Hashem!
Malbim: Yakov rejected possible reasons for Lavan's anger. (a) It is not because I sinned, and I lost Hashem's Hashgachah