The fact that he was loaned to Sweden should trump it though. Oh well..
This is ridiculous. You can't make up what "should" happen. There is a contract between the NHL and the SEL. The terms of the contact govern.
Nobody cares who was the original "owner". Think of it this way: the landlord owns an apartment. He rents the apartment to the tenant. Now the tenant has full rights during the term of the lease. The landlord can't come in and say, "I own this apartment, get out" or even, "I own this apartment, I want to be able to come inside." No, once you rent the apartment, the tenant has the right to it for the term of the lease and the landlord needs to get the hell out of the way until the lease is over.
Now, you can argue that the "lease" on Fasth should be over now that he's eliminated from the playoffs, but that is your wishful thinking. The terms of the contract are very clear: the "lease" on Fasth goes on until and including the WHC. We may not like it, but our opinion is irrelevant here.
People here can whine that these are the terms of the contract, but inventing stuff is not helpful, nor honest.
Every time people use the word "fair" or "justice", whether in law or politics or anything else, you can bet your bottom dollar they are not asking for anything that is fair or just, they just want to get some unfair and unjust benefit for themselves.
For instance, it is unfair for me to want to keep my money, but it is fair if the government taxes more of my money to give it to you. On the other hand, while it is fair for the government to give my money to you, it would be an outrage if your money went to me.
Same here. It is unfair that the SEL is trying to keep their player for the rest of his "lease" or to get some benefit for allowing the "lease" to be broken, but it would be perfectly fair for a lease to be broken with no compensation to the Swedes. On the other hand, if Sweden got an NHL player in violation of the NHL-SEL agreement, there would be calls for a Jihad against the whole Scandinavia.