I think it is really funny when people want to criticize composers for using their own music from past scores into other scores. Williams has threaded a couple of his originals into Indy, which I thought worked!
One example is track 10, in which he uses the same rhythm at 2:29 as he did for Summon The Heroes on 4:35 as a hurried drum pattern. It was nicely done with great sneaky intentions, and I liked it!
Another example, which is my favorite, is on track 13 at 3:22 at which Williams re-introduced the War of The Worlds theme heard on track 3 or 4, can't remember which, but it is so funny, because the scene is when the alien is revealed and it's ship. Nicely done Williams.
For the final one, Williams flirts with the rythm pattern from Holiday Flight from his Home Alone music, and reverses it to a run down on track number 3. He uses the same scale but faster for track 8 in the very begining and more.
To let everyone know, I am not at all criticizing Williams, but, it kind of reminds us that even the very best composers "teal" their own music. Is that a bad thing? I don't think so!
The whole "Horerism" thing from the reviewers I just don't get, for Horner was not the first film composer to repeat his music in other films, I think all composers have done this, so stop calling it Hornerism!

Trevor