He walked up to Walhberg's dad to apologize for what he did, hoping for protection in prison. Wahlberg's dad gave them a nod to take care of him; he did "kill" his daughter in law and try to cover the evidence in cement. Sebastian probably ended up dead after that or majorly f'd up, but my guess is dead. What do they care, they are probably there for life anyway.
although the writing and directing were absurd,the ensemble was great..simmons,o'hara,foster,ribisi made cliche characters complicated and human...we take supporting character actors for granted..