alt Hacker NewsDIN sync is not trigger based, it's a full clock protocol invented by Roland that has various different states. The fact is that not all DIN sync capable machines implement it the correct way, leading to slight differences in synchronisation, even between devices made by Roland.
Interesting, I'd be curious to read a technical analysis of the differences. DIN provides by far the tightest sync we've ever seen in hardware, so I question the idea that lag and latency are a defining feature of the protocol.