hacmp.out will only show you the messages of the RG move operation itself, not the cause(s).
First of all examine the log cl_event_summaries.txt in your cluster log directory. Any hints?

Possible causes for a failover:

1) Application monitor has fired.
If you’re monitoring your application(s) examine the log of the application monitor(s) “clappmond.application.resource.log” in your HACMP log directory.
The italic parts of the logname are variable and depend on your setup.
Also consider checking the logs of the application itself for a possible abnormal termination.
2) Heartbeat Network failure
Examine in /var/ha/log the network interface manager logs nim.topsvcs.interfacename.clustername
and the topsvcs.##.###.clustername log.
Again the italic parts are variable, “#” means numbers.
3) General clustermanager failure
Examine the logs named clstrmgr.debug.long.# in the HACMP log directory.

All the logs are hard to read, but you should find valuable information after all.

See the names and descriptions of all your HACMP logfiles with “/usr/es/sbin/cluster/utilities/cllog -s”

Find the exact locations with
odmget HACMPlogs | grep -E “name|value”