TBH, wouldn't of given it away, woulda stashed it myself, or after you got busted, just say it was cannabis paraphenalia or whatever, as long as it was clean, an so was you, they cant bust you for having a bong.
But, seeing as it's done, I dunno, I would be kinda inclined to make him pay you back.
If he don't, then just tell him where to go, if he was a serious mate he'd give you the cash or a replacement or some thing.
I'm not a violent person or anything like that.
Oh, and I know this isn't relevant, but someone the other day was talking about sugar in the gas tank? It don't work, however, styrofome, (like macdonalds packaging) an stuff, shredded an in the gas tank. well woah!

Styrofoam + gas = napalm.

but then, your just off probation, and I'm not a violent person, and this is just a correction, I'm not endorsing the use of this.