I don't blame Julius Schwartz for making that call. By way of background in the spring of 1968 the communist satellite country of Czechoslovakia (now know as the Czech Republic and Slovakia) experienced a wave of democratic reforms from their new leader, Alexander Dubcek. This raised hopes that perhaps there might be cracks in the Iron Curtain, but in August the Soviets responded in much the same way as the Chinese did at Tianamen Square (and as the Iranian regime is responding to the current unrest); they rolled the tanks in and started killing.
From Batman #213 (July-Aug 1969). The book that the unnamed Czech patriot raves about is indeed one of the finest comics in the entire Silver Age, and probably deserves a good look:
One of my all-time favorite covers ever; the use of a B/W negative really makes that last panel, where Batman suddenly unmasks himself, pop out.
That's the opening story, certainly on any Bat-fan's short list. The second story, the Jungle Cat-Queen, is my personal choice for the finest Batman story of the Golden Age. It's a great story, features the Catwoman, has multiple death traps and beautiful Sprang artwork.
The highlight of the rest of the issue is the terrific Sunday strip where the Penguin's real name of Oswald Chesterfield Cobblepot is revealed.
So overall the dad of Vasik, Lidunka and Evicka definitely scored a classic comic. What a shame that it would be another two decades before Batman became generally available in the Czech Republic.