Yes, that was not accurate and you're correct, it's still not clear what caused the first train to derail to begin with.
The way I looked at it is that the first train derailing wasn't a big issue, I don't think it caused any injuries. What was really catastrophic was the impact with the second train.
The machinist union requested the maximum speed to be lowered from 300 km/h to 250 km/h on multiple areas, the one where the accident happened being one of them. Both trains were driving under 210 km/h when the accident happened, so I don't think the "rattling" they reported was the issue.
As I mentioned before, this area was renovated last year, so attributing the accident to under-funding is highly unlikely. If the infrastructure happened to be the issue at the end, it might be because of different causes: eg. Planning the wrong materials for the amount of traffic / weather conditions / etc.
In general, when you talk about under-funding in the rail network it's often regional or small areas within the inter-city (larga distancia) and transport networks. High speed infrastructure is very well financed, it's not cheap to move trains close to 300 km/h.
1. The last 3 cars from the Iryo train (Frecciarossa 1000) derailed for unknown reasons. It's a straight line, so this is extremely rare.
2. The Renfe train (Alvia) didn't have time to break and hit the derailed trains from Iryo, the two first cars derail as a consequence of the impact.
3. The Iryo train(Frecciarossa 1000), that caused the accident, was manufactured in 2022 and it passed a technical inspection just 4 days ago.
4. The renovation of this specific part of the infrastructure finished on May 2025, so it's practically new.
Spanish high speed trains are one of the best in the world and it had plenty investment from governments of different sign over the years. This has nothing to do with the regional network (Cercanias) and the local struggles in certain regions.
IMHO, this is a horribly timed accidental technical issue.
The way I looked at it is that the first train derailing wasn't a big issue, I don't think it caused any injuries. What was really catastrophic was the impact with the second train.