Yes, that strange behavior (or similar) I've had yesterday too.
Situation: I'm in a combat fitted FAS on my way to the nearby CZ, no cargo racks fitted...
now interdicted by some npc named M.S., Elite Anaconda, exactly after launching the FSD, with standard talk "that tasty cargo...." yeah yeah... of course...
Good, I thought, let's kill that idiot.
After that (and my too lazy flying skills) I've got to 94% hull and some dakka ammo lost during that fight (these pesky fighter these elite annis have....)
Okay, we have time, let's go back to the Station to rearm/repair since it's close nearby...
Immediatelly next Interdiction. Same M.S. WHAT??

.
He never learns (but obviously had teleport escape pod as it seems, at some invisible Station nearby (System only has an outpost, no large landing pad)),
nevertheless, killed him.
I'm still at 94%, but more ammo lost.
Next try, back to station.
Interdiction detected.
FUC$$$
This time I submit-boosted away, I've never seen him again later...