Lots of unusual about that tornado. Not only the slow speed, but the tornado itself followed a rare path - moving NE→SW, the opposite of most storms. A rare condition as well is that the tornado popped up right inside the frontal lift boundary, so it curved along the frontal line itself. Again, pretty rare.
That system simply rode the frontal boundary down into N. Williamson, re-emerged briefly as an F-4 in Cedar Park (enough to take out half an HEB and a small part of a subdivision), lifted again, and re-emerged in West Lakeway, heading SW in the Bee Creek area, where it again dropped - as an F-4 down by RO Drive. It crossed 71 about 3/4 mlie east of the Pedernales Bridge, entered yet another subdivision, was ready to buzzsaw that to nothingness - and then just simply dissolved and lifted, this time for good.
I went out to clean up in that subdivision the next day. I drove out 71 and for about 250 yards the road itself was pulled up. There was a swatch of dirt left where the pavement was. When I got inside the subdivision, which had a lot of trees, I came upon devastation for only a small length- and then you could actually see the curve of the tornado's shape as is suddenly lifted. What was left was a clear arc - the curve of the funnel, where on one side nothing was disturbed, and "inside" it, everything was nothing but wreckage. I'll never forget that curved line, though.
Too much else to talk about, but that storm was heading straight for me - if it hadn't followed the curve of the front - in other words if the frontal boundary had been straighter - I probably would have not had a house. As it was, it curved more W and went 5 miles west of me.