I totally agree, using alt accounts is not prohibited here nor lying about having an alt and this even doesn't deserves a negative tag.
The accusation made in the OP is even baseless as the campaign they were participating in did not have any such rules, and even if it had it was better handled by the manager of the campaign by kicking the participant out and not by some DT tags.
Before making such conclusions, you should have read the whole topic.
1.) Bounty cheating has been in
several campaigns.
2.) This farm has been involved in merit abuse (admitted independently).
3.) be.open was engaged in account trading/changing/gifting check
reference from
suchmoon:
Lied about the account being hacked, then "gifted" to a friend. If you deal with this user you may find out it was hacked or gifted again if something goes pear-shaped.