If Juan Castillo doesn't run a zone blocking scheme, why have we run zone blocking every year he's been here?
I'll wait.
http://www.baltimoreravens.com/videos/videos/Inside-The-Game-With-Juan-Castillo/ddf63da5-cbb2-4565-86d9-ac4d6985979a
There's Castillo teaching zone blocking on the team's website.
Another source: http://www.baltimoresun.com/sports/ravens/bs-sp-ravens-zone-blocking-1108-20131107-story.html
The reporter writes, "The zone-blocking scheme hasn't changed drastically since Castillo took charge of the running game this offseason, but there have been tweaks. The Ravens have used more outside stretch runs, but the backs have been bottled up and the gains minimal."
In Nov. 2013, after Castillo arrived, Harbaugh is quoted as saying, "We've been an inside and outside zone team since we got here."
Also, the guy speaking in the radio clip you shared, Ross Tucker. While he was a longtime offensive lineman, he never once played for Castillo.