Everybody lost, not just GWS. McCarthy misses a whole year of AFL in a career of just 10 years, that's a big chunk. It will cost him future earnings (not worth as much as he would be had he played) plus experience. It wouldn't have calmed his mental demons at all and Freo still had nothing and will be getting a less experienced player than they would otherwise have got.
Nobody wins. The only difference is that had GWS done the trade, they would be put in this place repeatedly every year. At least now GWS players will think hard about signing contract extensions.
The biggest failure here was McCarthy's player manager, you'd assume he's been sacked. I'm tipping he told McCarthy to sign the extension knowing he wasn't entirely happy, but probably advised the kid that GWS would just 'let him go' if he wanted to anyway. He's done serious damage to his client's career and life.
Isn't this a bad thing for GWS? With McCarthy they had leverage in a trade, when pick 2 O'Rouke wanted out they had to take unders.
McCarthy (and Kelly and Barrett) extended their contracts just a few month after they were drafted. According to the GWS board not a single 2015 draftee has signed a contract extension. I'm not saying they're leaving or unhappy, but they might be a bit more reluctant to sign an extension knowing that GWS won't let them leave if their circumstances change.