Re: No video fire/smoke detection then?
The original french report notes that the detection and alert to the fire brigade was properly swift. They received the alert, they promptly alerted the emergency services after confirming it was real and left for their safety. While they were only three people on site, their proper procedure allowed for not having to search for potentially missing people, saving themselves and emergency services who had no need for a search and rescue operation. Also, they properly assisted the fire brigade on whatever they were able to.
The main problems where the electric isolation of the site, which could not be properly achieved well until two hours had passed and SBG2 was already a total loss, and the lack of proper water supply, either by the nonexistent internal fire suppressors or by the on-premises emergency water supply, which was under-performing. Fire could not be controlled until a large water barge arrived at 3am, which happened to be on Strasbourg port at the time. If not for that barge, the whole site would had been lost to the fire.
For the electrical isolation, they had to make sure all redundancy systems were either turned off or depleted, and that's what caused the massive delay before intervention: first, external power supply had to be cut off, which was not possible because the in-site breakers were too close to the fire and were thus not safe to operate, and the electric company had to be called to cut off supply to the area; second, the emergency diesel generators needed not to be started at all costs, overriding its default setup; third, as batteries could not be removed nor isolated they had to wait for depletion, and there was not an accurate estimate of how much time it would take to. All this waiting allowed the fire to develop.
This proved that the site was, after all, quite well designed against power loss. The problem was, precisely, that a total power loss was actually needed for the fire brigade to act.