FT - Question Regarding FTL use

Recently I was in a game of FT and something came up that I'm not to
sure about.  The scenario was this - two fleets cmae out of FTL into
a soon-to-be disputed system.  Fleet A actually arrived a turn prior
to Fleet B.  The referee for the game announced that it would be 8
turns before a risky jump to FTL could be made or 24 turns before a a
safe jump could be done.  I don't remember seeing this rule in FT.
Could this be from MT or does it sound like a house rule?  Thanks for
any insight.
		      Kent McClure