That was the wrong thought, but he was driving towards the right point. Each sport has its own internal culture that is created by the players and that extends beyond the rulebook. Within that culture, some things are acceptable and some things are not, and to the outsider, there can be a bewildering lack of moral equivalency between them.
In cricket, not walking for a nick will get you sledged by the opposition, and if you're a pro, the TV commentators might smile and suggest you've got away with one. You won't be spat at in the street, you won't have the opposition fans boycotting your sponsors' products.
If, like Paul Collingwood, you don't call back a player run out after a collision, or, like Ricky Ponting, you claim a 'catch' that has clearly bounced in front of you, you will face a righteous anger, even though the transgression has essentially the same result as the nick- the fall or otherwise of a single wicket.
Such things aren't decided by anything other than that internal culture. In golf and snooker, it's considered bad form not to call your own fouls. In rugby, it's worse to use fake blood than punch someone during the scrum. Football is even more vague, the language even more semantic [While Henry admits to cheating, he doesn't regard himself as a cheat].
There's no logic to any of it. Cricket just falls somewhere in the middle.