[Killebrew]

After the trade, the pitcher I traded turned into an absolute gem. The three prospects I got are now garbage.

How do you know he is an absolute gem? Is that after turning the scouts off? Either way the descrepency is likely due to different scouts opinions.

I've seen slight changes, but this was crazy. And if I am the team with the better scout, how come I am the one getting ripped off??

The way the OOTP scouting works a TERRIBLE scout might be more accurate on one player than a BRILLIANT scout. The TERRIBLE scout will be wrong much more often though.

When you are on a teams page, are you seeing the ratings through their scouts eyes or your own?

Not sure which team page you mean so I'll cover both...
The teams html page: I believe what you see here is a league default average scouts opinion, not the opinion of any specific scout in the game (meaning not your scout and not the other teams scout).
The teams roster screen within OOTP: This is your own scouts opinion, and I think when viewing other clubs you see their players through their scouts eyes, not your scout.

And how come the trade window shows different ratings than going to the individual team pages??

In the trade screen you see your own scouts opinion of the player first, then click on the player and the ratings should change to your own scouts opinion.... or vice versa - I have seen that question answered both ways. Since neither scout is guaranteed to be correct it really does not matter much which scout's opinion is displayed 1st in the trade screen.

Which is more accurate??

Whichever scout has a better rating should be more accurate more often. To find which scouts opinion you are viewing 1st and second (on the trade screen) I'd suggest making a note of your scouts opinions on some of the players from your own team roster screen, then compare them to the trade screen ratings to see which scouts eyes you view the player through first. If that all seems confusing don't feel bad, it is confusing. Just wait until you get into all the many different types of "average" rated scouts in OOTP.

Online player tip: I have heard that the top 10 prospects html pages display the players real talent & rating (without the scout-view dicing), so if you are dealing with young players, that is a good way to keep up with those online league sharks.