Honestly...it could be any number of things. I've put plenty of unsavory folk behind bars in my time. Anyone with a grudge and enough men to get the job done could have tried.

[He's strong and isn't to be underestimated, especially with a Vision that can freeze an entire field of people in place. But that doesn't matter if they were able to catch him at his most unguarded with no backup, no one knowing where he was...

He got sloppy, plain and simple.]

Or...to state the more obvious, it could have been the work of the Abyss Order, attempting to find even more ways to cripple Mond's support network.