
Quoting
Mr. Knowitall
If there is a provision in the lease that allows for early termination by a co-tenant, and the co-tenant used that provision to end the lease early, then the co-tenant has every right to do so. I have no access to the lease.
If the co-tenant caused a portion of your security deposit to become forfeit as part of an early termination, and you would otherwise have recovered your share at the end of the lease, then you can ask your former roommate to reimburse you and may be able to recover that amount in small claims court.