I'm not suggesting there is any other reason for the IRA to be buying Semtex, but the fact remains that it was the IRA that blew shit up.
Not that I'm very comfortable with that argument, either tbh.
I guess I view it similarly to Iraqi (or East Timorese, or countless others) seeking compensation from BAE Systems, rather than the actual aggressor.
I'm not suggesting that Libya (or BAE, or whoever) 'get away' with their part in shit, just the concept of who can/should impose those settlements an that.