I can believe that one of their SAM systems types was upgraded to improve performance against HIMARS. I just doubt it is as easy as that quote makes it sound. A Russian poster on tanknet quoted an article that indicated the problem with engagements were the short window of opportunity (specifically given as 10 seconds) and the small diameter of the rocket head on. I believe that article was discussing the Tor system, which explains that short engagement window. I would think a Buk system's search/acquisition radar would allow for a lot more warning.