On a serious note, it's not likely more/better reflective clothing would have helped. It sounds like the driver was deliberately and abruptly deviating from the normal lane to bypass traffic. It was not a decision made with the safety of others in mind.
This was a pretty good example of something similar that happened an year back, and I'm sure there are more examples (I just never bothered to pay attention to them).
On a serious note, it's not likely more/better reflective clothing would have helped. It sounds like the driver was deliberately and abruptly deviating from the normal lane to bypass traffic. It was not a decision made with the safety of others in mind.