Fossils by themselves do not prove evolution, but evolution makes certain predictions, and fossils support those predictions. Among those predictions are that we will find transitionals from one group to another (there are transitionals), that a species that evolved later will not be found in an earlier strata (so far so good).
Fossils are just one piece of evidence for evolution. Many other evidences exist, which I think is what he was trying to say. When he said "it's proven, we have all the steps", he was referring to the fact that, given enough time, one animal species can change into another type of animal. He was referring to the fact that there are transitional fossils that show these transitions.
The second point, is that evolution doesn't "progress" in the way that humans would look at progression. For example there's nothing about the evolutionary process that necessarily leads to anything being stronger or smarter. The "progress" is toward the ability to reproduce effectively. Some animals may find that losing their eyes saves energy if they live in a dark environment and won't use them anyway (like cave dwellers). Some animals may find that keener, sharper vision helps them to hunt better (like eagles). Having super good vision or going blind, neither would be beneficial for the other. So it's relative to the environment as to whether a specific trait is helpful or hurtful. I am pretty sure this is what the scientist was trying to express.
Kent Hovind was just blanketly saying that no fossils count as evidence for evolution. That basically means that even if you had EVERY single step of the transition, that he would still not accept it. That's just complete, willfull ignorance. We do have enough steps for the land mammal - whale transition to draw meaningful conclusions from it, but people like Hovind are incapable of looking at the evidence in an honest way.
When the guy said "fossils don't mean anything, ... we don't need them", he was referring to the fact that even in the complete absence of fossil evidence, there is still substantial, very good evidence for evolution. The fossils are just the icing on the cake. The fossils are evidence of evolution, but we don't need the fossils to establish evolution as fact. DNA, comparative anatomy, taxonomy, embryology, and other areas of evidence also support evolution.
The guy on the tv show talking about the tree being inverted is being taken way out of context. There were more phyla in the Cambrian than there are today, but the phyla that survived from then have branched out and changed so much that the branching tree analogy still makes sense. For example Chordates, the phylum which all vertebrates and other types of chordates belong to, looked more like this in the Cambrian:
Not so much like this: