Sadly for the NBA and anyone who really cares about professional sports, the Tim Donaghy case is like a barrel of toxic waste in the well water.

Instead of being critical of an official's call, fans now openly suspect the NBA (and the NHL and the NFL) of dictating the outcomes of postseason games. Instead of trusting in the fundamental integrity of the games, fans have good cause to wonder whether there isn't some secret script.

This kind of thinking predates Donaghy's admission that, as an NBA referee, he worked games he had bet on. The difference now is that conspiracy theorists sound less crazy than the known reality.

So when Joey Crawford is assigned to work Game 4 of the Western Conference finals, San Antonio Spurs fans immediately call shenanigans. Crawford was suspended last season after ejecting Tim Duncan for laughing at a call while he was on the bench, and he called a dubious technical foul on Spurs coach Gregg Popovich earlier in the playoffs.

When Game 4 then ends with a controversial non-call that seals victory for the Los Angeles Lakers, well, it's easy for partisan fans to add two and two and come up with five.

A more neutral observer (like, say, me; what do I care who wins this series?) can see that Derek Fisher clearly fouled Brent Barry as he set up to attempt the Spurs' final shot. The foul clearly occurred before Barry's three-point attempt, and so should have led to two free throws. A neutral observer also would note that such non-calls are all too common at the end of close games.

Conspiracy? Not likely, and here's why.

First, if David Stern really does send encrypted messages dictating the outcome of games, the last thing in the world the NBA would do is assign Crawford to a Spurs game. The key to a successful conspiracy is to make everything look as if it's on the level.

Second, if the motive for all this is to set up a Boston-L.A. matchup to boost TV ratings, then why push the Spurs to the brink of elimination in Game 4? If it's all about TV ratings, wouldn't it make sense to extend the conference finals for as long as possible? Two more games, including a Game 7, would mean more revenue than a slight increase in the ratings for the Finals.

The problem here isn't that the games are fixed. The problem is that fans have been given too many reasons to believe they could be. Too many instances of poor officiating have left a sour taste after too many big games. And it is no secret that all big-time sports survive on TV money, which of course grows with the ratings.

If Donaghy would fix a game for a couple of hundred bucks, why wouldn't a commissioner fix one for tens of millions?

It's not just the NBA, of course. Tracking fan reaction - via e-mails, blogs and message boards - during the Flyers' recent playoff run was telling. There is no doubt that a large percentage of fans believes that the officials deliberately influence the outcomes of games.

Example: During the second-round series against Montreal, Flyers center Mike Richards was called for a penalty on Canadiens star Alexei Kovalev. After seeing it live and on two replays that night, I wrote that Richards did trip Kovalev - although it was his stick, not his knee, that upended the Russian forward.

The reaction from readers was immediate and angry. So much so that I watched the play on YouTube.com about 15 times the next morning. Every time, I saw Richards use his stick as a lever to lift Kovalev's leg out from under him. It was obvious from the reader reaction that others watched the same clip and saw Kovalev take a dive as Richards delivered a clean check.

Many readers expressed the firm belief that the referees would not allow the Flyers to beat the last remaining Canadian team in the tournament.

The Flyers eliminated the Canadiens in five games. That's not a very effective conspiracy.

But here's where the Donaghy thing comes in. All by himself, in plain sight, he was able to influence the outcomes of an unknown number of NBA games without ever drawing attention from the league. That proves the impact a referee can have, and it proves that he can have it without anyone's being able to prove he's doing so intentionally.

And that, sadly enough, makes all the conspiracy theories that much more credible.

There is one final, compelling reason to believe that the games are still legitimate, though flawed. The risk of scripting games to boost the Nielsen numbers is just too great. If it ever did get out that these games are fixed, the ratings pretty quickly would drop to somewhere around 0.0.

Contact columnist Phil Sheridan
at 215-854-2844 or psheridan@phillynews.com. Read his recent work at http://go.philly.com/philsheridan.