I 100% disagree. For every close game (which I have had many) I have had an equal share of turn arounds, and blowouts. Early might set the tone for some games but just as many I have witnessed have come back around. Some comps are built around comebacks and sometimes they just happen after a few critical mistakes.
Dominion isn't over until the last points tick down to 0.
Anyways, on a more general level, the early game of Dominion matters much less than in SR. Dealing with a carry that got fed for the first 10 minutes off good jungle ganks on some bad player is a hell of a lot harder than taking a few points back. You can recover in Dominion usually just from stepping up your teamplay, while in SR someone on their team will often be too farmed to lose unless they make a HUGE mistake and your team doesn't.
Hell, even for how much people complain about Dominion leavers, they're not as bad as for SR either. Out of 1600 games on SR, I've won under 10 4v5s where an early DC returned, and it was even rarer that that the missing person on our team was useful when they reconnected. In only a bit over two-hundred Dominion games, I've had a couple where we were losing badly early due to a DC, but they came back and we managed to turn the game around.