It is most definitely a stacked switch. The management allows for creating LAGs across units.
Here is what I am starting to think. I am wondering if the load balancing that is set from the console "Configure Management Network" settings isn't the same. If I add a NIC from that menu, but don't create the LAG on the switch, vCenter shows two NICs with one in standby mode. I did test to see if disconnecting the active link caused failover to happen and it didn't.
Stephen