According to your link, hosting an exit node was not a crime by itself, this person pretty much encouraged the illegal activity

The Austrian Court found that this activity may lead to criminal liability for aiding and abetting of a crime of distribution of child pornography when coupled with other circumstances. Of course, mere provision of Tor Nodes would not be enough to establish at least indirect intent (bedingte Vorsatz), which such aiding and abetting under criminal laws usually requires (§ 5 StGB).
In order to find such circumstances, according to PCWorld, the court cited transcripts of chat sessions uncovered during the investigation in which the Weber told an unidentified correspondent “You can host 20TB child porn with us on some encrypted hdds”, “You can host child porn on our servers” and “If you want to host child porn … I would use Tor.” Weber defended himself against this on his blog saying: “Yes, this logs existed – Yes, i recommended Tor to host anything anonymously, including child pornography – Yes, this is of course taken out of context.”