I don't see how it works as a Trojan horse. I don't think it plays - all the apps using Crashlytics will switch to a different service rather than have their data flow to Twitter. No way Expedia wants their data flowing to Twitter (or anyone else).
Looks to me like a talent acquisition. While Crashlytics was likely popular, I think they likely had limited revenue opportunities given Hockey App and Crittercism.
Really - it's a race to the bottom on these crash services. Switching costs would seem to be pretty low - so my guess is that the VCs saw a quick out.
Congrats to the team for the acquisition.