Yes, certainly a cautionary tale and good that you could tell it.
My workshop is so well sealed (and not that spacious) that I generally even cut dry or arrange ventilation, and rarely use an open flame in there (and not for long!). Even the surface grinder is going to be vented to the outside.
Welding is most certainly off-limits within the confines of the workshop and if a plasma cutter ever graces my collection that, too, will be outside the machining area.