The thread started with this:
Spanish government failed its citizens.
That people crossing the border died is again, tragic, but not a failure of the Spanish government towards its citizens. That would be more or less like calling the Ukranian government a failure to their citizens because Russian soldiers die in their attacks on Ukraine.
I would say that on second thought a bit of failure on the side of Spain was lack of monitoring by intelligence services of Moroccan social media for signals of these kinds of attacks, but remember that this is unprecedented: Previous 'mass' border crossings were in the thousands, not ten thousands of people. Hindsight is 20/20 here.
The only significant problem that remains is that apparently a bunch of the crossing Moroccans were unaccompanied adolescent boys and you can't just say to minors "tough shit, go back" according to Spanish law. It's up to you whether you think that is well-intended and necessary protection of children or merely a weakness to be exploited by children. In the latter case you have to make the argument whether and how, outside of these coordinated efforts, it is actually a big problem. I personally think it very much does NOT warrant saying "Spanish government failed its citizens."