ITA. They should have established it.
I used to do a lot of driving around - both in Toronto and out of town. Never failed to surprise me how many single and even pairs of shoes I'd see on the road and off to the side of the road. Lots and lots of them. Never understood the phenomenon except to think they fell off the backs of pick-up trucks, or kids threw them out the window.
IF the single shoe found by Lillian was one of the pair belonging to MTR, it shouldn't have been far from the missing one. Anyone searching for it should have found it, whether it was LE or MTR himself. If it had been MTR, he would have also picked up the one found by Lillian. So, I suspect this single, missing shoe had no relation to the Shaq pair, which is why no more was said about it. Frustrating for us, but unimportant to the investigation.
JMO