Saliva drug test

Okay please no judgement here as it’s a legit question I have- we didn’t know this would be happening!

My husband and I live in CO where it’s legal. He went in for an interview and had smoked that morning (I’m thinking like AT LEAST 4/5 hours between, at the minimum) and they ended up giving him a saliva drug test on the spot. I’m just curious on if this could make the test come back positive for marijuana. I get that it’s legal here but I also know companies don’t quite like to hire people who smoke for fear of coming to work high and things like that.

Also, they emailed him the next day to complete his background check so it seems like everything’s okay? I just wanted to check as we’re used to urine tests and not saliva (sounds stupid I know). Thank you!