The Dyson tweet happened less than two months after the privileges committee came up with a set of rules explicitly stating that tweets criticising the Speaker were a serious matter.
In November, Little and Hipkins found themselves in hot water after criticising Carter's decision to block one of its members' bills from going before Parliament this year.
Hipkins accused the Speaker of "massive political interference in the parliamentary process".
The heat was largely removed from the Labour MPs' comments on the final day of Parliament last year, when Key apologised for and withdrew his "backing the rapists" comments.
After that apology, Little announced that the party had written to the privileges committee to say that the comments made by some Labour MPs were unparliamentary, and expressing regret for them.
Carter thanked Little sincerely.
In a decision released today, the privileges committee, chaired by National MP Chris Finlayson, recommended that the House accept the expressions of regret by the Labour politicians, and take no further action.
"We recognise that it is never acceptable for members to reflect on the Speaker or other presiding officer in a way which alleges bias or otherwise brings the House into disrepute," the ruling stated.
"However, the context for these three questions of privilege reveals that, on occasion, significant tension and disorder in the House can cause members to behave in ways they may later regret."