Is properly sealed bottled water ever unsafe, even in developing countries?

Question

The highly-ranked Delhi Belly question has a number of answers that allege bottled water from minor/unknown brands may be contaminated or otherwise unsafe.

Now I've heard of tap water being sold as spring water (primarily in the West, where tap water is safe to drink anyway). I've also heard of various scams involving refilling empty bottles with sketchy water and reselling them to clueless tourists, with India in particular once being notorious for this, and many guides still instruct you to both buy only double-sealed bottles (plastic & cap) and crush used bottles to avoid this.

However, I've drunk plenty of exceedingly sketchy looking but properly factory-sealed bottles of water (Exhibit A below), and as far as I know I've never gotten sick from one.

So: is properly sealed bottled water ever unsafe? Research and news articles preferred over anecdotes.

Clarification: I'm aware there have been incidents of lead in tap water, bottled water being accidentally contaminated with chemicals, etc. I'm really more interested in cases of people drinking bottled water and immediately getting violently ill (Delhi belly style), the way you would in many places if you drank tap water contaminated by sewage etc.

Answer 1

The generic plastic bottle cap can be sealed outside of a factory. If you ever bought craft beer on tap take away, they will pour it in a plastic bottle and then seal it with a plastic cap. Then it looks completely legit.

Plastic cap can be put on a bottle together with the plastic ring which holds it fast. But then it will hold the bottle with plastic spikes and will not go off without breaking ring apart from the cap.

So it's totally unsurprising that somebody could easily replenish empty water bottles.

Answer 2

Yes, sealed water bottles can be unsafe.

If you look at the comments on the question, two different links are given for historic events in the western world, well known brands.
(Link one, by from a comment by @Stuart F)
(Link two, from a comment by @Fattie)

And this is from companies that are/were reputed to be safe. In my country, the Netherlands, the quality rules for bottled water are lower than for tap water, although still high enough for safe water as a rule.

In the whole world it is a case of trust in the company and the location you bought it.

Some people are extremely good in re-filling bottles and making you think that it is factory filled, but even real factory filled bottles do have a bit of risk.
On the whole, much less of a risk than tap water in areas where the tap water is not safe, but there is never 'no risk'.

Many of the contaminations that result in Delhi Belly and alike do not stay alive long in closed off water bottles, days maybe, weeks in some bad cases but water which has been bottled for a longer time will mostly show a different kind of contamination.