I don't know for sure. All I know is that the AMF (Autorité des Marchés Financiers, Quebec "equivalent" of the SEC) froze Dominic Lacroix assets on Jun 13 2017[0]. Yet, his employees were still getting paid and he launched Plexcoin even if a court order was forbidding him to do so.

Maybe the AMF had information about accounts in USA and tipped the SEC?

[0] https://lautorite.qc.ca/en/general-public/media-centre/news/...

EDIT:

More information: The court order preventing him to launch Plexcoin was issued on July 20[1]. He did not comply­ and was charged for court contempt in September. The court found him guilty on oct 17 2017[2].

[1] https://lautorite.qc.ca/en/general-public/media-centre/news/...

[2] French only - https://lautorite.qc.ca/grand-public/salle-de-presse/actuali...