I think it was a very minor contribution ... they wrote a pseudo-Algol program as a form of documentation of their network protocol and were concerned about checking the grammar/syntax of the program (people actually cared about the quality of documentation back then), and I wrote a syntax checker for it in Meta V, as it was on hand because it was written at UCLA (I don't know whether it was Dewey (Val) who designed and implemented Meta V or someone else) and was used by people in the Comp Sci Dept. to design programming languages. But the dept was shifting to networking at the time (the IMP had just arrived) under the direction of Leonard Kleinrock and through the efforts of pioneers Steve Crocker, Vint Cerf, and Jon Postel (all of whom had attended Taft High School together) ... this is why the authors of that network protocol were visiting UCLA. I got involved because I worked for Crocker, under the direct management of Charley Kline, who was the fellow who made the first ever networked login.
it's interesting to see programming language advancement cited as a major contribution to the development of a network protocol