Init script changes for mongod

We have mongodb(version 3.0) in production in standalone as well as in cluster mode.Currently we were facing issue saying "unclean shutdown detected hence unable to start mongod".

1. After debugging we got to know mongod was showing different pid in (O/p of ps -> i.e

ps -eo pid,cmd | grep "/usr/bin/mongod" | grep -v "grep" | awk '{print $1}') and there was different pid in /var/run/mongodb/mongod.pid.

2. In second scenario testing team performed multiple restart operations in that case we got situation where mongod was in ruing state but pid file were missing.

For 1st scenario we simply changed init script to check if ruing pid is different than pid present in mongod.pid then simply write ruing pid inside mongod.pid file.Any help to understand these scenarios will be much appreciated.Thanks