Was he flirting at all? Guys? Girls?

I had a job a couple of months ago in which I travelled to another city to attend a training course. A guy from my office travelled with me and sat next to me in the training room. During one of the breaks, we got talking and he did the most of it. At one point he was talking about previous jobs he had done, and he'd done a lot of work in fisheries. He was leaning back in his chair with his hands behind his head, legs stretched out, looking up at me every now and then as he spoke. He was talking about the special clothing he had to wear in the water, these wader things that you wear over other clothing, then he told me it was so hot one day that he just wore his boxers beneath the waders. :S And he was smiling and laughing the whole time. I'm probably reading into it this too much, but does any of this sound flirty? Do guys normally talk about something personal like that to a girl they don't know very well?