Oh dear. You haven't read my post at all, Marcus.. or so it seems.
If you have watched the video concerned you would have picked up on that error.
The diagram is correct in so far as what each filter does.
Now, Marcus - have you owned a Vax Mach Air? There are very few vents at the front by the motor to allow the motor filter to expel. This is why if you look at the white mesh at the top of the grid, it traps dirt that can be seen to the eye. Yes, it is not washable for the very reason that it sits above the motor!
Also there is no motor at the top of the Vax Mach Air.. so even if the filter is washable, combined with the NLOS filters AND the post motor filter, HEPA can rightly be achieved.
SEBO do things differently Marcus - yes there is a filter above the motor on the Felix but the exhaust filter at the front and that motor filter combined on the Felix contributes to its S-Class standard. The X series has the roll filter which is independent from the motor carbon filter.
A paper pleated cone filter or grid filter does not necessarily mean it is automatically HEPA, in my experience. Some vacuums dependent on their design either overly complicate things OR in terms of bags, add layers of filtration to compensate for just a paper pleated cone filter at the exhaust.
Clearly if a vacuum cleaner has a larger exhaust, then yes, that is where the claimed "clean air" will exhaust from.