Pool Manipulation at Los Al?

[Southieboy]

5k win bet cancelled at Los Al before post, then 3k put in after the start.

[Stillriledup]

Commentators were saying on TVG that the horse flipped in the paddock.

[wisconsin]

And threw the rider on the backstretch during warm-ups.

Saw the betting, very strange, horse was 1/9, 2/5, then, all of a sudden 6-1 and was 6-1 at the off. At the wire, the final odds were 5-2. After the 5k was canceled, the 5 dropped to 3/5, but only had 4k on him, wound up with 7k total. What's up with that?