Thanks for the info, Tom. I'm wondering how many Compestellas have you refused to hand out because the two stamp rule wasn't followed? Does the office keep stats on the total denied per year?
I do not know, as I doubt this refusal count is kept. But, in my experience they DO make exceptions.
For example, if you walked from Pamplona or Saint Jean Pied de Port and had a single stamp each day, and completely forgot about the two-per-day from Sarria rule, staff can usually tell if you did, in fact walk the distance.
The fact is that long-walkers, those who started as Lisbon. Madrid, St. Jean Pied de Port, Le Puy, Barcelona, etc., just look act and smell different. If they proceeded directly to the Pilgrim Office on arrival, without first showering, changing clothes and storing all their gear, the typical long-walker pilgrim just has the aura of someone who has been the distance. I have previously likened the comparison to someone who has served in military combat and "been there - done that" - versus a new replacement who has been in theater perhaps a week - barely time to get dirty.
Conversely, "short-walkers," from Sarria, Tui, Ferrol, Oursense, or Vigo, for example, lack that tarnish and wear that the extra month, and related weather and challenges can leave on the typical pilgrim. They typically have clean clothes and gear, lack stains, tears or field expedient repairs to gear, don't have medical dressings on wounds, are not limping, beards and hair is still neatly trimmed. Caked mud is not evident on walking sticks and footwear. Ladies nails are still done and polished. You get the idea?
The staff behind the counter, and most repeat volunteers, can spot a long-walker versus a short-walker at 30 meters. During the summer, groups of short-walkers may have bright, uniform t-shirts attesting to the group they are with, or the magnificence of their 118 km pilgrimage from Sarria to Santiago. Hey, it's their Camino and they can tell the story however they want.
The point is, if you are a long distance pilgrim, the staff can usually tell and will consider the totality of your credencial and your stamps. However, if you are a short-distance pilgrim, staff are likely to be more by-the-book. The determination to accept your story is still case-specific.
Hope this helps.
Tom