Nothing in bigfix that I am aware of. The only thing I can think of is doing a manual cache but it requires you have the file bigfix was going to install. Make a copy of the file and name it the file hash it is looking for. Place the file on the root server in the downloads. i.e. for windows %install path%\BES Server\wwwrootbes\bfmirror\downloads\sha1
This will push the old version. If you want to go though this you might want to create a copy of the current fixlet and modify the relevance to meet the new version and change the action script to use the new has. Also rename it so its easier to find and remove later.