Hi Lawrence,
Yes, I've seen this video before I bought the 'TC-645', this one is a Japanese version I believe. Thanks for spotting that one for me. I didn't think about any rubbing with the erase head then of course!
It's just catching the tape to the left side of the erase head. So I'll later look into fitting a broader tape lifter with hard wearing characteristics etc. Only needs to be a few mm wider diameter.
An oversight by Sony?