This all depends on the operation you're performing, in a clone, yes the VM object will be locked from making any changes to. afaik, the Locked field is not something you can set but done internally within the APIs, if you take a look at the description, it says the following:
If the state of the task is "running", then this property is a list of managed entities that the operation has locked, with a shared lock.
This property is primarily set based on the entities being modified and if the task is in a 'running' state. If you operation requires a lock, then it will not allow a user to remove/delete.
Probably be a good idea to have some type of communication with your customers or even setup change control so you don't run into this problem ... if it's actually occurring.
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William Lam
VMware vExpert 2009
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