Check out http://www.pbcc.org/dc/hebrew/HebVerbCharts.pdf.
You've got an imperfect verb in the first (yiqtol) and a perfect (qatal) verb in the second. The first passage views perishing as a process, i.e. wearing out like an old garment. The second views it altogether as a single event, i.e. at the moment of death. It's simply a different aspectual focus. One is over a duration and the other is not.
Thank you. So, at the end of the process, as in the old garment, there's no use for it any longer. Is the final outcome for both that they are no longer around?