Business was operating in a residential area.
Didn't need to inform the authorities they were operating, and even if they did, would anything change?
Guaranteed, that there was no risk assessment performed for their activities.
Would be interesting to know if they were inspecting and testing their bottles, some of those in photos look old and corroded.
Untrained and underpaid staff, probably working too long hours per day and per week.
Lack of basic health and safety training for the staff. Probably not competent to handle these cylinders (refilling, manual handling, moving loads, dangerous goods etc.) either.
Using unsuitable, poorly maintained and likely modified and overloaded vehicles for transporting dangerous goods.
Etc.
If this had happened in the UK, expect big fines and criminal prosecution for the business owner.