Is this my fault?

[GPSnV1]

We had flooded streets in the morning commute so I put my 2004 4.4 sport in the S drive both to slow down and speed up.
I came up on a light about a mile from my house. I don't think the engine was really warmed up yet. Anyway I was fooled into thinking that I had fully stopped and when the light suddenly went green, then I pushed the accelerator to take off. Due to the weather and traffic, this was just a moderate tap. Well I had not come to a full stop and when I started forward it felt like I had been hit from behind.
Unfortunately this has happened 4-5 other times. Am I being clumsy or should I mention this when I take the X5 in next week for some scheduled repairs?