Does it sound like my son was sleeping or could he have stopped breathing?

So today when I was putting my son down who is 8 months for a nap after he was done with his bottle I went to go put him in the crib and he was a little pale and I thought that was weird so when I put him in his crib he was really limp now to let you know he didn't really take a nap all day but when we were in the car for maybe 30 mins. So when I set him down I umed he stopped breathing because when I felt his stomach it didn't move and I felt it for about 5 seconds and still no movement and so I freak out and grab my phone while holding him to call 911. While on hold another 15 seconds has gone by I start saying his name, he is a pretty deep sleeper we can be doing things in his room even drop stuff and he wont budge when he is sleeping, so while saying his name no reaction, I start to tap his shoulder nothing. Then as soon as the fire department gets on the line about 20 seconds total has gone by still saying his name and nudge him I notice his eyes move and I cont. to do the same thing then he sits up in my arms doesn't gasp for air or anything like he couldn't breath and lays back down so I then cont to say his name and nudge arm and he jumps up and starts smiling and laughing and acting normal. I then tell the 911 guy I think he is fine and I get off the phone with him and watch my son closely he is acting like he normally does. So did I freak out for nothing or do you think he could have stopped breathing? Also wanted to add he didn't seem like he was in distress when he got up after everything was breathing fine.