Authoritatively speaking, the standard line is:This debate cycles about 3 times a year and has been cycling since the early 2000s lol. You can almost set your watch to it
Guys let's all chill a bit and move on. Who cares... we're on J-10C which is nothing like the Lavi now and that's not even exciting anymore. Chinese industry have some better projects they're working on these days.
At this point, we can comfortably let those naysayers just take the J-10A = Lavi thing they love to hold onto. If the Russians copied, the Israelis copied, and the Americans copied, there is no shame in it. In fact a fair bit of skill is required.
We've moved on from the 1980s. If they really want J-10A = Lavi, let them have at least that much. It makes them feel better about themselves.
-J-10 developed from Chinese research into canard fighters during the Cultural Revolution. None of these fighters ever left the drawing board or prototype stage.
-J-10 received considerable Israeli input, mainly in the FCS design, as the Chinese had no domestically-built FBW fighters.
More entertainingly, if people bring up the J-10 as a Lavi knock-off, you're better off trying to talk them into thinking the J-10 is a Eurofighter knock-off instead and having brave, original arguments over that subject.