Jobs lied to Steve Wozniak. Atari gave Jobs $5000 to make Breakout for Atari. He told Wozniak he got $700 so Wozniak took home $350.
Was it an ethical mistake? Sure. He should have at least disclosed that he was receiving the bonus money, even if he didn't want to share it.
But claiming it was a "major ethical mistake" seems fairly out of touch with reality.
And of course, taken in the context of all of the good things they did together, it was completely insignificant and Woz has said as much.
As a rule, Apple gave stock to employees prior to the IPO, many of whom got rich. But some employees weren't eligible according to the criteria Steve (really, the board) came up with, and so they did not receive stock. Their criteria were typical for the time.
Woz and a few others felt bad about this and shared some of their stock.
Whether those ineligible people "deserved" stock is a matter of judgement...