at least you did not need a poker to open the stick up.
...waaaayyy too many opportunities to turn this into an even sicker joke, in light of the tampon comments...
Anyhow, I'm wondering if, when rolled, the string (looks like a bale tie, personally, but could be a curing tie or the likes) was "under" one leaf of the typical three or four for the filler, stuck to the bottom of one of the leaves, and finally ended up placed onto another leaf, resulting in a sandwiched string in the filler. Or, as yet a second alternative, I've seen newer/ trainee rollers use a string to start the roll of the filler, which is to be removed before applying the wrapper or cap. Did someone just forget to remove the "training wheels"? Still, as it appears in the top photo you posted, one would think it hard to miss.
This is just speculation, but perhaps the cigars are bunched and/or binder- wrapped (bunched into the binder, not wrapped with the wrapper, I mean), then set aside in a
tied bundle to age... of which, the tie may be the same string type, color, etc as the offending one... ok, I know it sounds crazy and is giving them the benefit of the doubt and then some, but perchance they mistook the offending string for the end of a bundling tie? It's the best I can do to explain it -- sure, it's a "hand-made" product, but it's also an "eye- inspected" one.
Just my 2 cents worth,
ZugbugPete