It could have been improperly spooled onto a reel, if those were involved. It's a tad more sensitive
in this regard to even film distribution than some other films, though if the film had actually buckled
and touched it would show as vertical streaks of whatever mush. Sometimes a pinch of EDTA helps.
But given basic technique, it's relatively cooperative, and nothing particularly weird about the
processing variables. Obtaining correct contrast is a different subject.