In the episode Goku asks Gowasu about the potara.
Why Goku and Vegeta defused in the past when it was suppose to be permanent as Goku was told.
Gowasu doesnt know about their fight with Majin Buu, but explains that the potara fusion lasts 1 hour maximum if those who are not supreme kai, use it.
Now this doesnt necessarily have to mean that Vegetto defused in the past, only because the timelimit was over.
Being inside the body of Majin Buu, after releasing the barrier, could still have effect on Vegetto to defuse.
I dont think that the barrier of Vegetto was released in Majin buu, exactly at the timelimit of the fusion.
That would be too much coincedence.
Old kai doesnt know about the timelimit apparently.
Nor does the universe 7 Supreme Kai.
Nor does anyone else who watched the fight on tv screens in other world.
So basically if Vegetto had toyed too long with Buu, he would have defused before he could enter Buu to save the others.
All of this is not a plothole, but it may be a bit shakey.
That nobody in universe 7 knew about a timelimit on potara for non-supreme kais.
Although on the other hand, maybe no non-supreme kai ever fused with it so therefore nobody knew yet.
Why Goku and Vegeta defused in the past when it was suppose to be permanent as Goku was told.
Gowasu doesnt know about their fight with Majin Buu, but explains that the potara fusion lasts 1 hour maximum if those who are not supreme kai, use it.
Now this doesnt necessarily have to mean that Vegetto defused in the past, only because the timelimit was over.
Being inside the body of Majin Buu, after releasing the barrier, could still have effect on Vegetto to defuse.
I dont think that the barrier of Vegetto was released in Majin buu, exactly at the timelimit of the fusion.
That would be too much coincedence.
Old kai doesnt know about the timelimit apparently.
Nor does the universe 7 Supreme Kai.
Nor does anyone else who watched the fight on tv screens in other world.
So basically if Vegetto had toyed too long with Buu, he would have defused before he could enter Buu to save the others.
All of this is not a plothole, but it may be a bit shakey.
That nobody in universe 7 knew about a timelimit on potara for non-supreme kais.
Although on the other hand, maybe no non-supreme kai ever fused with it so therefore nobody knew yet.