Hey, I managed to get around this in two different playthroughs. No guarantees (this is going to sound stupid, I'm warning you), but the difference for me was skill. If you get Peter van der Graaf in big chunks, it locks. Zooming way in and swinging back and forth over his head, so that the ID bar fills in lots of little pieces has helped me get around this twice---it almost seems like the sound file activates before I reach 100% either when I move off the target or back on it.
Yes, I know it sounds stupid, as if it wouldn't matter. But it seems to have worked for me twice.
First off, played through three times, bought both pieces of intel in all three. No modifications to any game files.
First time, did not experience this bug.
The second time, I experienced the lock on Peter van der Graaf but merely loaded, IDed him and went on my merry way.
The third time, I got stuck and experimented. What finally worked for me was the swingy method.
I'd love to hear if I'm a crackpot or if this worked for anybody else. At the very least, I hope it won't hurt for people to try.