The person I talked to said that if any thing was using ram that shouldn't would stop using ram when I opened up in safe mode. I'm not tech savvy but it worked for me. AS I type this I'm using 4.2 GB ram before I called I was using 7.5 GB of ram.
This is correct, but not for the reason you or the Apple tech think.
When you boot into safe mode a lot of stuff doesn't run, and you are doing a fresh start. Much of Yosemite's RAM management is to cache what you have used and closed (say an app using 2GB), in case you decide to re-open it. If since the last boot you haven't used that app, Yosemite won't have loaded it and won't be caching it (Yosemite doesn't have ESP to know what you are going to use, only what you have used).
Now, using that 2GB as now cached RAM, in case you want to reopen it isn't a problem, Yosemite will only keep that 2GB of RAM allocated (and loaded with the App), as long as Yosemite doesn't have a better use for that RAM space, as soon as it does, say you want to load a different App, Yosemite frees up that 2GB and the new App can then use it.
So the fact that 7.5GB of your RAM was "in use", isn't a problem and isn't quite true in the old meaning of "in use".
When you reboot (even a normal restart), Yosemite will start with less code (especially if you don't restart with "load previous" ticked, that simply restarts that apps that were running and guess what? Uses the same RAM as before the restart). Booting in Safe mode doesn't start anything non-essential so starts with a lower RAM usage. As you open Apps and close them, even in Safe Mode, RAM used will climb.
Learn to ignore the RAM usage figures EXCEPT the Memory Pressure graph (should be green or yellow), and the Swapping figure (should be low, but what is acceptable is up to you, I was concerned at swapping several GB as I am on an SSD, but the speed wasn't a particular issue as swapping was fast, now I have 16GB I swap nearly zero and the system is even better at responding, others get concerned if you are swapping
at all, IMHO swapping up to a GB is fine).
Oh and the 3GB you are "saving" by what the tech told you to do, it will bring you no benefit whatsoever...