Why is this transaction stuck? https://blockexplorer.com/tx/286fefb79f1b0a14526997e8c7bcb4bd7a5665c953586f6bbcd09e441b192d3f this is my transaction blockchain hash

This is first time I've actually seen something like this - the buyer sent me $200 (at least he says) and the $250 came to my wallet but $50 is Unauthorized or something like that. The transfer is seems to be stuck in limbo.

I was trying to wait - I asked about it on LBC they have no idea...

Can anybody explain to me in what circumstances can a processing transaction become stuck?
If this transaction does process will it transfer to my wallet or reverse to sender account?

Is this situation avoidable and how long it at maximum could it take?
A simple explanation would be great I'm a beginner btc user.
The transaction spends an output which itself is unconfirmed, it means there's a chain of requirement back two transactions which may or may not be completed. In this case, one previously must be confirmed before this one can enter a block. 


  If this finally process will it transfer to my wallet or reverse to sender account?


It may be confirmed, it may never be confirmed, or it may be invalidated by a double spend, there's no way of knowing this in advance. In general this is why the advice is to never give payment for an unconfirmed transaction, until it has a reasonable number of confirmations there is no assurance it will ever confirm. With LocalBitcoins in particular there is an internal escrow tool which you can use to avoid this in the future.