Have you ever packed a schute?
Nobody who packs parachutes calls them 'schutes' so I'm going to go out on a limb and guess you are not a rigger or even a sport jumper
Because everyone knows that parachutes are ejected with explosive charges, or in the more modern versions, a bottle of compressed air.
No, sport parachutes are deployed by hand either with a pilot chute deployed by hand or by a spring loaded pilot chute deployed by a ripcord. There is an automatic activation device for the reserve parachute that uses a small pyrotechnic charge inside a cylinder that propels a cutter to sever a fabric closing loop that allows a spring loaded pilot chute to deploy.
I have gone skydiving, and the acceleration (or decelaration if you prefer) is rather violent. Without doing the math, I very much doubt that anything would be "popped off the top of the chute".
It could easily happen depending on where the object was. if it was inside of the parachute or inside of the deployment bag.
A rock of that size does not simply find its way into a plane, or into a skydiver's pocket. Gravel-sized rocks, sure. Something the size of your fist? No, just no.
Can easily find its way into a parachute, however. People who don't skydive think that parachutes are packed with surgical precision. Not the case at all.
It is actually very easy to explain the delay once you understand how modern square ram air parachutes are designed.
Modern canopies are roughly rectangular and are composed of 7 - 9 cells in parallel.
Each cell has an opening at the nose of the canopy that is roughly rectangular. The cell tapers down until the topskin and bottom skin meet at the tail. This creates the parafoil (wing) that looks a lot like an airplane.
On the ground, it is very easy for objects to end up inside of a cell. When you pack the parachute, these objects can move deeper into the cell (maybe all the way to the tail).
Opening is a very violent process during which the parachute expands from being in a bag approximately the size of a woman's purse to full flight which, depending on the parachute, can be anywhere from ~100 - 400 square feet.
My parachute is a Sabre 2 170 which means it is just under 20 feet wide and 7 feet deep.
This means that on opening, an object in the tail of the parachute would have to move forward 7 feet. Depending on the pitch of the canopy and what maneuvers I am executing, the combination of the angle and gravity could easily keep an object inside the canopy for more than 5 seconds. The object (even a good sized rock) would stay in there for the entire flight.
You have to also consider that this was a wingsuit deployment, which has different opening characteristics than a traditional vertical deployment because the jumper has much more forward velocity and less vertical velocity. This would affect the orientation of the canopy and would have an effect on how objects inside the canopy would move around.
I have personally seen grass and twigs come out of my canopy. I have seen a video from a friend who saw several socks come out of his nose as his canopy had been sitting unpacked next to a laundry basket the night before. Parachute riggers that do inspections or repairs on canopies have great stories of things they have found inside canopies including phones and drugs.
So while the meteorite story is exciting, the idea of a rock falling in your immediate airspace doesn't sound very impossible if you're a skydiver. I'd not call it common, but it's certainly not a rare occurrence. While not the most newsworthy, the simplest explanation is the guy packed a rock in his parachute and god knows how he didn't notice when he packed but it wouldn't be the first rock to take make a skydive.
If you could run this as a business operation, I wonder how much you could charge people for "space jumps"?
I am a licensed skydiver, and I can tell you that the way "normal" jumps are priced is there is a boarding fee generally $10-13 USD and then you pay $1 per thousand feet of altitude. This is whether you get out at 3,000 feet or 13,000 feet. But this is out of an aircraft without needing supplemental oxygen or equipment.
Specialized jumps cost more:
Hot air balloon jumps are usually around $45 and you get out anywhere between 4-6k feet.
Anything above 15,000 feet requires supplemental oxygen, so these jumps can be more expensive.
A civilian HALO jump from 30,000 feet costs around $375.
However none of that applies in this case because of all the specialized equipment for the stratos mission.
For example, the bottom of the capsule is one-use-only. Upon landing, the capsule's bottom absorbs the force of impact and "crumples", so every flight requires a replacement. There is a pressure suit which needs to fit the jumper. There is a custom parachute rig made by Velocity.
Also, the time to altitude takes a very long time, and the winds need to be just right. So it is not uncommon for them to wait days or weeks to have a window to try. They also have a large ground team. So this whole production would need to spin up for each "jumper" meaning at best you could do one or two jumpers every few weeks, at worst, one every month or two.
Not to mention each jumper would need to have a base line skydiving skill set that exceeds what most sport jumpers possess. Figure you would need to have several thousands normal skydives, including HALO jumps, before you could even begin to train for a stratos jump. Training for stratos jump would include many jumps wearing the space suit and custom velocity rig, which is not a standard rig so it has different deployment and emergency procedures. This training would need to include wind tunnel time to work on falling in a stable belly to earth orientation. It would also need to include jumps from an aircraft.
As a business operation you would likely need to charge hundreds of thousands of dollars per jumper, if not millions, and only allow "customers" who meet the qualifications.
So really, you'd have to invest several years in skydiving and have a scrooge mcduck money pond waiting for you at the end of it.
OR, you use the red bull money from all the idiots who drink red bull and you have an awesome adventure on their dime