I don't think the "password changed" message is something meaningful. That is the widespread practice in password changing on regular basis to increase security of the account. Some services even force you to do that from time to time, IMO.
If you want to change your password for security reason but someone reporting you did something wrong (such as, hacked account, sell account) to bounty manager and makes you banned from campaign, you can create a clarification signature message with your staked Bitcoin address on
this thread .