History..
1. A list of stakeholders for RSU were established on this thread.
How at that time the one became a stakeholder? Was it free?Yes, I see it was free.
2. RS Dev then decided to create assets on NXT AE so these first hand stakeholders can trade their stake. So anyone can sell their stake or anyone interested that missed the train can also buy if they are interested. These assets are temporary until the RS software is build. At this point, the stakeholders either can claim their RSU stakes via assets or can choose to hold on to their stake in the original stakeholders list.
What consequences such a claim had (any transfer of funds/the record in some/nxt public ledger/other)?
The transaction record is recorded in the blockchain which can be seen in the below link.