my snipers were on hold position, but they started moving by themselves at times.

edit:
notice the hold-pos snipers on the ditch near the cliff on north end of the SW base:
- in replay i noticed it first at 16:01 but was fast-forwarding before it
- at 16:30ish another starts moving, i think trying to chase a welder that got out of range
- at about 17:25 another starts moving to chase a minotaur that got out of range, moving south

(i don't think i manually gave any of those orders)