Yes, Failed node can not issue ASUP. Log files of failed node are included in CONTROLLER TAKEOVER ASUP issued by alive partner node, so you do not need to collect logs. I could not find a way to access files of faild node using scp, ftp, or systemshell. Only parnter mode of node shell is accessible.
To access older logs and ASUP, use rdfile on partner prompt of node shell like below.
Check latest ems log and latest WEEKLY_LOG ASUP(Sep 4) of failed node(cluster-02)
cluster::> run local
cluster-02/cluster-01> rdfile /etc/log/ems
cluster-02/cluster-01> priv set diag
cluster-02/cluster-01*> ls /etc/log/autosupport
cluster-02/cluster-01*> ls /etc/log/autosupport/201510040025.1.files