I came across an unexpected behaviour:
apparently Chrome 36 and up supports both prefixed and unprefixed 'transform' property.
So, if you set initial transform values on an element (not with GSAP) like so:
someElement {
-webkit-transform:rotate(30deg);
transform:rotate(30deg)
}
and do
TweenMax.set(someElement, {clearProps: 'transforms'})
only the unprefixed version is being cleared and the rotation remains on the element.