Tool Quickstatements seems to be identified using the text #quickstatements in the edit summary, which is only added with temporary batches. In batches as listed here, only the tag is added, which I suggest to use for identification (instead or additionally). Depending on the version it is OAuth CID: 699, OAuth CID: 1253, or OAuth CID: 1351.
UPD: Not all QS edits actually have the QS tags, some use the Widar tag (see supertask) and have the mentioned hashtag added to the edit summary. That means both means of identification should be implemented.