I do believe it is Bobby Lamm dubbed in. The 45 edit is a mono mix and doesn't have that in it. Top 40 stations back in 1971 didn't play the album version with that in it, the played the single mono edit. But since most oldies stations only had access to the cd versions the album version became heard more often, same thing goes for Beginnings, and BS&T's Spinning wheel, oldies stations again only had the almum versions on cd, so the original 45 edits weren't heard unless you actually spun the original 45. I have noticed a few oldies stations be politically correct and play the single edits but it's rare.