Holmes made similar argument in Eugene Debs (1919) case yet is remembered as civil libertarian for supporting free speech against court majority in post-WW1 Benjam Gitlow (1925) case. His analogy in Charles Schenk case mentioned above is good example of why maxim 'all analogies being suspect, some are more suspect than others' should be kept in mind. Note that Holmes says that free speech doesn't protect person who *falsely* yells fire in crowded theatre. There are, of course, times when it is legitimate to do so - when there is a fire. Well, WW1 was a fire and Schenk was yelling to let people know.
Key part of Holmes' majority in opinion in Schenk is really found in passage where he writes that Congress can prevent 'substantive evils' and that the matter should be decided by 'proximity.' In other words, actively opposing war (evil) during war (closeness).
Holmes' dissent in Gitlow, in which the majority held that speech could be permissibly curtailed if it had a 'bad tendency' to lead to illegal action (Gitlow has been convicted under NY state 'criminal anarchy' law for distributing literature that called for establishing socialism through general strikes and direct action) certainly doesn't dispel logical fallcy in Schenk. A single soap-orator (Gitlow) in a time of political reaction (1920s) stands a low chance of success.
Court's 1951 decision upholding Smith Act (prohibited advocacy of 'violent overthrow' of US government) and conviction of 11 CP members under that law, in effect, said that well-organized, disciplined movement advocating revolution in a 'tinderbox' (hey, I can use fire analogy too) of unstable political conditions stands a greater chance of success.
btw: if memory serves, when the Court made it more difficult to convict communists later in 1950s (overturning Smith in 1957, I think) then-Chief Justice Earl Warren asked Eisenhower (who had appointed Warren in 1953) what he thought the Court should do with communists, Eisenhower's reply was 'I would kill the SOBs.' Michael Hoover