There was an Austrian passenger in 3rd Class called Wenzel Linhart, who did not survive. But I suspect that the man you have in mind is Rudolf Linhart, who was interviewed long ago by Radio Prague and claimed to have worked on Titanic as a waiter. There is no record of any such crew member on board. Linhart's colourful story included memories of the crew sleeping in hammocks, and of the officer in charge of his lifeboat shooting people in the water. He obviously had a lively imagination.
Yes, that's it. But I think he has benn aboard because there was a framed picture of Titanic (but it was Olympic)that White Star Line gave him as present. Now it's somewhere in a museum. I read about his imagination, I read transcript of an interview with him.
Vitezslav, the names and other details of surviving crew members can be found in the signing-on sheets which can be viewed on this website. They were also carefully listed on the Carpathia and again for the official inquiries following the disaster. You won't find Mr Linhart in these lists. Neither will you find the name of Josef Kielbasa, another Czech who made a similar claim and took part in the same radio interview in 1962. Or Viktor Halva, who claimed on another occasion to have been a passenger. Or Karel Stanke, who was said to have been an unlisted member of the ship's group of musicians. Over the years, many false claims have been made to sell a story, or to gain attention or even a little celebrity status.
The story of the framed picture (now apparently in a museum in Mohelnice) related I think to Alois Jelitek, who was (or claimed to be) a crewman on the Carpathia rather than the Titanic. .