Haven't heard it put quite that way. Of course, "opening up a can of worms" is like taking the cork out of the genie's bottle. Once you open the lid, the news just keeps getting worse.
I suspect your expression means that A has revealed something about B which is going to get him in a lot of trouble with C, probably resulting in his getting his arse kicked big-time.
Edit. Clive is probably right. Probably the person who opens the can is the one who delivers the ass-whupping.