He's referring to the Eastern District of Texas which is infamous for patent trolls. A small number of judges find in favor of patent trolls far more often than the rest of the nation.
As the link notes, the Eastern District of Texas forum-shopping strategy for patent lawsuits was more or less shut down by the Supreme Court in a 2017 ruling [1]. This suit against comma.ai is, probably as a result, filed in the District of Delaware, since comma.ai is a Delaware corporation.
https://en.wikipedia.org/wiki/United_States_District_Court_f...