Playing Rules with string pin machines
In the BigA constitution, section 18 of the playing rules deals with issues arising from pinfall.
"If string pin machines are in use, BTBA guidance concerning dealing with erroneous resets of pins shall be followed."
BTBA guidance can be found in the BTBA General Playing Rules, Section 6
Rule 6a - Legal Pinfall Freefall,
Rule 6b - Legal Pinfall String,
Rule 6c - Illegal Pinfall,
Rule 6d - Illegal Pinfall String
In Section 6d-Illegal Pinfall String there is only 1 entry:
Any pin which was standing at the point the guard starts to drop but is not reset must be re-spotted