If you slid left by mistake, no worries! We’ve got your back!
While liking a profile, you can see the Undo (the circled arrow) option next to the "X" symbol.
If you slide left by mistake, click on it. Only your last Dislike will be rewinded.
As a dua.com Premium user, you get more Undos! This means that you can easily recover from unintended likes.