Puggo - Jar Jar's Yoda said:

I still don't buy that explanation. I never saw the comic or the "Making of SW".

I'm reluctantly willing to concede that I might not have seen Luke miss with the grappling hook. Perhaps my "memory" of having seen it is based on other similar scenes in other movies, where it is customary for the protagonist to miss the first time or two. But regardless of the lack of corroborating evidence, I am quite certain I saw the full Biggs reunion in the theater multiple times mid-1977. Unlike the hook, the Biggs scene isn't an incidental thing, but a lengthy scene with significant dialogue. I don't expect people to believe me, but I don't mind... I'm confident my memory will be vindicated someday!

And you're sure you never heard the radio series either?

If THX-1138 had a larger fan base, there would have been plenty of debate over people remembering that lost scene I found. So your memories could very well be correct.