Captain Picard originally lied at the end of a Star Trek: TNG season 2 episode and it would’ve had major ramifications for holodeck technology.

Summary
- Captain Picard’s lie in the original ending of “Elementary, Dear Data” would have changed the holodeck.
- The original ending of the episode would have raised questions about the ability of holodeck characters to leave.
- The implications of Moriarty leaving the holodeck would have affected future holodeck adventures and raised ethical concerns.
Captain Jean-Luc Picard (Patrick Stewart) lied in the original ending of an iconic episode of Star Trek: The Next Generation season 2, and his lie would have had major implications for the holodeck. For seven seasons on TNG, Captain Picard led the USS Enterprise-D as it explored the galaxy and encountered all manner of strange new aliens. TNG took the Federation even further into the future than Star Trek: The Original Series and introduced even more advanced technology, including the holodeck. The holodeck allowed the TNG writers to experiment with genre and send the Enterprise crew members to various historical time periods.
In Star Trek: The Next Generation season 2, episode 3, “Elementary, Dear Data,” Lt. Commander Data (Brent Spiner) and Lt. Geordi La Forge (LeVar Burton) embark on a Sherlock Holmes-inspired adventure on the holodeck. When La Forge asks the Enterprise computer to create an adversary that can outsmart Data, the holographic recreation of Professor James Moriarty (Daniel Davis) gains a level of self-awareness. Moriarty then wishes to leave the holodeck, but Captain Picard assures him, correctly, that this is not possible. In the original ending for “Elementary, Dear Data,” however, Picard’s statement was a lie.

Related
Star Trek: The Next Generation Cast & Character Guide
Star Trek: The Next Generation has one of the most beloved cast of characters in all of science fiction. Here are the major characters of the classic.
Captain Picard Lied To Moriarty In The Original Ending Of “Elementary, Dear Data”
And his lie would have completely changed the holodeck.
One of the major reveals in Star Trek: The Next Generation’s “Elementary, Dear Data” comes when the holographic Moriarty draws a picture of the USS Enterprise. Data then takes this paper off of the holodeck and shows it to Captain Picard. In the episode as it airs, there is no explanation given about how this paper can exist outside of the holodeck. The original ending, however, used this moment to show that Moriarty, too, could leave the confines of the holodeck. In Captains’ Logs: The Unauthorized Complete Trek Voyages, TNG season 2 showrunner Maurice Hurley revealed the original ending, which had Picard lie to Moriarty about being able to leave the holodeck.
It was Star Trek creator Gene Roddenberry who nixed “Elementary, Dear Data’s” original ending, claiming that it made Captain Picard look underhanded. Hurley thought it made Picard look clever, but Roddenberry got the final say. Regardless of what it would have said about the character of Captain Picard, the original ending would have had major implications for the technology of the holodeck. Plus, Data is “Elementary, Dear Data’s” true star,” and making the issue of Moriarty’s existence even more complex might have bogged down the episode, and made the story more about Picard’s lie.

Related
Star Trek’s 20 Best Holodeck Episodes
Star Trek’s holodecks entertain, fulfill fantasies, heal old wounds, train cadets, and malfunction badly, as seen in these 20 best episodes.
“Elementary, Dear Data’s” Original Ending Would Have Raised Too Many Questions
What does it mean if holodeck characters can leave the holodeck?

While it’s plausible that a piece of paper could continue to exist outside of the holodeck, a sentient being leaving the holodeck is an entirely different matter that raises many questions. Moriarty asserts “I am alive, and I am aware of my own consciousness.” If Moriarty can leave the holodeck, that means the holodeck can create a form of life, which would be a huge development that would have far-reaching implications for Starfleet and the Federation. Not only would this have impacted future holodeck adventures on TNG, but it also would have drastically altered the story of the Emergency Medical Hologram known as The Doctor (Robert Picardo) on Star Trek: Voyager.
In TNG season 6, episode 12, “Ship in a Bottle,” Moriarty returns, demanding to know why the Enterprise crew has not found a way for him to exist outside of the holodeck. “Ship in a Bottle” furthers the discussion about the rights of holograms and Moriarty’s sentience. He has clearly become more than the Holmes and Data villain he was initially created to be, and Captain Picard understands the significance of this. Star Trek: The Next Generation often wrestled with complex moral and ethical questions, but the original ending of “Elementary, Dear Data” would have complicated every future story involving the holodeck.