Considering how FireWire worked in comparison to USB that's not particularly surprising. The host machine was more or less out of the way while the FW interfaces did their thing instead of requiring constant hand-holding.
Kind of: it used DMA, but the buffer size wasn’t infinite. At the time, Windows 9x and Mac OS would lose data if you ran anything demanding. Windows NT and Linux might, depending on drivers and the exact nature of the other process’ activity.
Considering how FireWire worked in comparison to USB that's not particularly surprising. The host machine was more or less out of the way while the FW interfaces did their thing instead of requiring constant hand-holding.