Thanks, Laurie and Admin for your explanations. In Sibelius "extra" rests can be "hidden" so they are assumed, and not explicidly present in the score. I guess the "layering" feature of NWC affords the same end result.
Click on St. Francis Xavier/score --> See in Measure 3: dotted quarter (A-flat), eighth note rest , then eighth-note (B-flat), then quarter-note (G), then a quarter-note (F)
This is 4 and 1/2 beats in a 4/4 measure. The eighth-note rest is "extra". This happens a lot in the scores. Compare my transcription:
Now the question is what are they doing wrong. I tried editing the file, and removing the dot makes no difference. Is the voicing wrong ? What do they need to do to correct it ?