Unclear on the Archeological Context

I was out for a walk the other day.  As I have mentioned in the past, my "archeology eyes" work full time, so when there is something even slightly out of the ordinary on the ground I notice it. 

To my surprise, sitting by the curb in our rather modern street I saw this:

This is an artifact that will be instantly recognizable to approximately 0.001% of the population.  But I am among that group.  This, you see, is a small part of one of these:

Warner's Safe Cure was a 19th century patent medicine.  The proprietor of same was a certain Hulbert Harrington Warner, who made his first fortune selling fireproof safes.  He carried the distinctive trade mark over into his second career, and made a very successful brand of a variety of "Safe Cures".  It is quite a tale, and to my surprise there is actually an entire blog devoted to the man and his products.  If you're interested, here ya go.

But I am less interested in collecting this sort of thing than I was in times past.  Also this is far from a rare artifact, millions of bottles were manufactured between roughly 1880 and 1910.  No, I am simply curious as to how this shard ended up where it did.

It was just sitting there.  No nearby construction site, no recent work on the roadway or boulevards.  I wondered if the recycling truck had dropped it. I mean there is no reason to doubt that a homeowner finding this would toss it in the recycling tub....but it was all by itself, and what are the odds that a bit of circa 1890 glass-which must be a minuscule to non existent component of local recycling-would be the only thing to fall off the truck?

Perhaps a kid found it on a nearby hillside, this sort of thing does turn up there.  I guess he could have carried it around a while, walked a few blocks and set it down. 

It points out the bigger challenge of archeology.  Things are not always where they should be.  Floods, later construction, movement by critters and cold weather (these last two are delightfully called bioturbation and cryoturbation!), it just makes it difficult to be sure about dating things.  Finding it where I did would seem approximatly as probable as getting a denarius back in change at the Vindolanda cafeteria!

I think we can exclude local time-space distortion, but I will keep my eyes open for mysterious glowing lights from now on.