I think if you put all the weed from your joint into a bong your question would be answered ;) That would certainly fuck me up more anyway!
I think with the example you've given, the reason why you've had to stealth smoke should be taken into account (ie you're in a rush or the feds are walking over). If you have to bun down a spliff quick, quite often it's in a more stressful situation, which could counteract the effect. When I was younger I remember once coming home from work angry and stressed. Drained a joint in 2-3 mins.... didn't feel anything!