Sim, aconteceu por acidente e de propósito
Por acidente
O episódio de duas partes DS9: Past Tense .
Mais tarde, descobriu-se que as partículas de cronitrons, que estavam alojadas na armadura ablativa do Defiant e eram emitidas por seu dispositivo de camuflagem, eram responsáveis por mudar a pessoa transportada a tempo.During a transporter accident above Earth in the USS Defiant caused by chroniton particles, Benjamin Sisko, Julian Bashir, and Jadzia Dax were sent back in time to mid 21st century, just before the Bell Riots.
Além disso, no mesmo episódio, Kira Nerys e Miles O'Brien viajaram no tempo para vários anos diferentes (1930, 1967, 2048 e, finalmente, 2024). Sua viagem foi, no entanto, intencional.
Editar: também é interessante que:
While devising "Past Tense, Part I", the writing staff of Star Trek: Deep Space Nine chose the transporter as a form of time travel which hadn't been employed before and wouldn't require much exposition. "We had never used the transporters to beam people back in time, which I thought would be kind of a neat way to do it," stated Robert Hewitt Wolfe, who co-wrote the story for "Past Tense, Part I" and co-wrote the episode's teleplay. (Star Trek: Deep Space Nine Companion, p. 197)
De propósito
O cronograma da Federação "Relatividade" do século 29 foi equipado com um transportador temporal, que era capaz de transportar um indivíduo no tempo e no espaço. Foi visto em VOY: Relatividade .
The timeship Relativity was equipped with a temporal transporter, located at the starboard-aft of their bridge. The transporter was used in unison with several other technologies, such as temporal sensors and temporal shields. Temporal sensors allowed for the precise moment and location to be chosen, and temporal shields were raised before making any temporal transports.
When Captain Braxton, commander of the Relativity, attempted to save the Starship Voyager from destruction due to a temporal incursion, he used a temporal transporter to beam back and retrieve Seven of Nine moments before the ship exploded.
Como mencionado acima, Kira Nerys e Miles O'Brien viajaram intencionalmente em busca de Benjamin Sisko, Julian Bashir e Jadzia Dax.
Editar: Eu destaquei as pessoas transportadas, como Kyloren reformulou sua pergunta.