Kishi made Minato look like a retard, this guy died as the only person who knew about Tobi, and instead of scribbling a message in the dirt about tobi or heck, even telling the frog he summoned and then sent to jiraiya about tobi he died with crucial info about a major threat to the village. The only reason obito didn't return the next day and steal Naruto is because of plot. This also caused the Uchiha to get put under suspicion which eventually led to the massacre. Minato made HUGE ****-ups.
The part with the frog happens in chapter 504 page 9 Minato summons him and tell's him to store himself in Jiraiya because he has the key to Naruto's seal. All Minato had to do was tell the frog to tell jiraiya about tobi and his space/time abilities. This would massively change the story. It's completely obvious that Kishi didn't plot out his story in advance. Otherwise holes like this wouldn't exist.
The part with the frog happens in chapter 504 page 9 Minato summons him and tell's him to store himself in Jiraiya because he has the key to Naruto's seal. All Minato had to do was tell the frog to tell jiraiya about tobi and his space/time abilities. This would massively change the story. It's completely obvious that Kishi didn't plot out his story in advance. Otherwise holes like this wouldn't exist.