The thing is though even if LTE was used in agreement with FRAND, Apple refuse to take part in and agree with FRAND so therefor that still wouldn't solve the situation for Apple.
The only plausible way for Apple is if somehow they don't infringe on Samsung's patents.
I disagree with your post entirely. First off, you cannot get an injunction with FRAND patents -- you can however sue for financial reimbursement.
Most importantly, if Apple does not directly implement LTE, but only uses components that are licensed for LTE (e.g.: Qualcomm chips) then Apple need not "take part in and agree with" FRAND. There are tons of patents that go into creating a LCD monitor. If I sell kiosks that embed LCD monitors I don't need to go license those patents -- I just need to ensure I buy LCD monitors from suppliers who have obtained proper licensing. Apple need only worry about Qualcomm having proper licensing.
In all likelihood, Qualcomm is also offering indemnification related to LTE patents for their components and as such Qualcomm assumes all liability from Apple in such an event.