Had he done so without error, I might not have noticed this for some time as I am now sitting at the wrong end of a bad ClearCase connection that means I don't run the differencer on changes as frequently as I used to. Fortunately (?), there were several errors that stopped the code from working altogether.
Memorandum: if my function is carefully generating a new DataSet (which I've carefully "new"ed), you might want to consider returning it rather than letting it fall on the ground completely unused and passing the original, malformed for this purpose DataSet into your function where it will do, well, nothing at all useful.
Animated discussion ensued.