The Mystery of the Abandoned Vomit Bag

The Mystery of the Abandoned Vomit Bag

June 5th. Radnor Township, Pennsylvania. A Bed Bath and Beyond employee encounters something horrible: a semi-hidden bag containing 35 pounds of human vomit.
The punchline? They found another one the week before.
So many questions, so few answers.
The bag was placed "about 10 parking rows from the store behind a tree." This makes it sound like it was tucked away in a far corner of the parking lot. Could it be the work of a crazed transient who is sleeping in brush alongside the parking lot?
Suburban parking lots often abut abandoned scrubby areas where transients sleep. So it's not entirely impossible. Satellite imagery shows that, although the Bed Bath and Beyond is on a commercial road with a lot of other big box stores, there is also a lot of green space around the margins.
Or was the "tree" one of those decorative trees in the middle of the parking lot itself? The overarching question being, was the bag meant to be found?
Not to state the obvious, but 35 pounds of vomit is a lot. A gallon of fresh water weighs eight pounds. Vomit would be somewhat more dense, so let's say a gallon of vomit weighs ten pounds. That would be three and a half gallons of vomit (more or less).
Is this the work of one mad barfer? Or is it the work of several people? Frankly, this smells like a fraternity prank. Vomiting into a bag and hiding it in a Bed Bath and Beyond parking lot is definitely the sort of thing that bored young men would be inclined to do, doesn't it?
It could also be the work of an ex-employee. (Or both!)
Would DNA evidence be able to identify and convict the person(s) responsible? According to the FBI's DNA website, "Samples such as feces and vomit can be tested, but may not be routinely accepted by laboratories for testing." Because they are too gross? Or because they are difficult to test? Doesn't say.
On a sadder note, bulimics are notorious for vomiting into containers and hiding them, in order to conceal evidence of their eating disorder from concerned friends and family. Anecdotes of bulimics hiding vomit abound on the internet. This could well be the work of some person with a mental illness who desperately needs clinical treatment.
That being said, only the rudest bulimic would stash their evidence in a parking lot for someone else to clean up. Bulimics of the world, please properly dispose of your collected vomit in a dumpster!