Can an Oracle Database request a system crash (One Instance Crash)?

I am Junior Database Administrator at a Bank and there was an issue that caused the Oracle Database Instance one to crash (We have two instances). So the system rebooted itself and everything is working fine now. But the bank's DBA consultant said the Database requested the system crash. I tried to google on it but couldn't find any thing on it. My question is, can oracle db request a system crash (crash the instance that has the issue) if the db is experiencing issue with the OS? FYI, It is running Oracle RAC Grid Infrastructure