What would going to court buy you? He can call his buddy that doesn't live there anymore and have him give his 30 day notice so they both have given notice.
In the end you need to re-rent the place so you can spend the time in court for maybe one more months worth of rent or take the 30 day notice as coming from both parties and agree to terminate the lease.
I had a unit with 2 roommates on the lease. One moved to CA and never told me. The gal still living there wanted the bigger unit so I let her move in. I could have said I can not let you move until I get notice from both of you. I wouldn't have gained anything by enforcing the terms of the lease.
The ultimate goal is to be fully rented with paying tenants. Sometimes enforcing the lease to the letter and spending time in court does not help with the ultimate goal.
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