I think the first brother was probably a fragment of his warning, which he then repeated.
And depends, he may be fuzzy on the exact time, or he may not actually live full time in Jotunheim, he may commute, and sleep at Asgard, which would be easy enough to do with the Bifrost. (when not out drinking and gambling, this vision would have arrived when he was locked up in jail, otherwise he presumably would have been in his own bed)