[gohrt]

"no chance" means making a claim that there will never be 2^N devices generating IDs simultaneously (for N somewhere around 30-60)

2 machines can have the same MAC addresses (they are reprogrammable) and can operate at the same microsecond.

"aren't randomly generated" is not practical constraint in a high-speed distributed system (where you don't have time for synchronization overhead).

[Goopplesoft]

Its an infinitesimally small chance. You'd need a mac collision, must be generated at the same time, and a uuid collision. Even at the largest scales (Google et all) the probability of that happening is effectively 0.