That translation it's wrong, “ay cabrón" it's kinda an “oh shit".It depends on the context but that's more accurate.
it could also mean "damn!" or "no way!", it's common a expression for when you encounter something that's unexpected, tho it has mostly been replaced for more vulgar words, in current times.
It could also mean WTF. Easily replaceable for ALV "a la verga" or ancient "en la madre" which all mean the same. It's a common expression for surprise between Mexican people. Penises (vergas), mothers (madres) or bastards (cabrones) don't have anything to do with the phrase unless context dictates so.