anrkitec, there is no question I believe you. What you describe is quite standard, and smart practice. Actually, I assume that there was a bit of snow on the wings, making it difficult to see if there was ice underneath, which can be really bad news. They were most likely sweeping the snow. They shouldn't have been chipping the ice. That is the domain of hot wings, props, and inflatable boots.

When I was an undergrad, I partially put myself through school flying corporate and commercial, even running a bit of Part 135 charter now and again. There were several times when I actually had the passenger hold the brakes while I climbed out on the wings with a broom, near the departure end of the runway, to check for ice. Boy, those were fun times!