Now they say oxalates in diet likely don’t affect kidney stones and if anything, tea may help keep them away:
http://www.whfoods.com/genpage.php?tname=george&dbid=48
Years ago I started drinking iced tea instead of soda. I was drinking about two quarts a day. Within a year I had an humongous stone. I now drink one to two cups a day and after a recent surgery the xray revealed no more stones. I was also eating a salad every day with spinach which is also high in oxalates. Not any more.
My urologist told me what he believes about oxalates and after my experience I believe what is said about them.
A single article that raises doubt based on no scientific evidence is not enough to get me thinking otherwise.