HA, Host Down, not restart VM on another node

Hi.

ESXi5.0

last night one of my host NIC card failed , and i have my management and Virtual machine on a single nic. However our storage was still up

HA isolation response was set to  "leave powered on " .

due to which VM's were not powered on an a diff host, Then we realized that all my VM's are also off the network and i need to start the VM on another host, so we manually did a hard shutdown of the host , expecting the HA to restart those VM's on another host,

For our surprise it did not restart the VM's on another host , i just want to know why it did not restart on another host

Thanks a lot...