Tick transmission from grooming

Question
I own mobile grooming vans.  We have a customer who claims that her dog was severely infested with ticks after a grooming session in our van.  She claims that she found ticks on her dog immediately after his groom and now she has an infestation that has cost her hundreds of dollars in vet bills.

I've tried to assure her of the following:
1.  After each groom all surfaces are sanitized and vacuumed.
2.  At the end of each day, all hair, debris, trash, towels (used or unused), used blades, water are removed from the van.  Van is sanitized and all crevices are vacuumed.
3.  Once a week, everything is removed from the van (table, cabinets, tools) and washed.  Her groom session occurred the day after a weekly scrubdown.
4.  We've had no parasite issues either before or after her groom.  Nothing has been reported by customers or by our groomers, nor have we personally seen any indication of any sort of infestation (vans, hair and towels come to our house so we'd be infested if vans were infested).

Am I mistaken?  Could there have been a risk to just her pet from something in our van that would have resulted in an immediate and massive problem?

I tried to find some pertinent information applicable to grooming to give her but while I can find information on ticks, I can find no mention of risk of transmission from groom shops.

Any  thoughts?
Thanks
Cheryle

Answer
This sounds preposterous. You did not say where she lives nor did you see the premises. You did say that you that you keep strict rules about your business. Does she have other pets? How can your groomer not have seen this if there was such an infestation? Did you talk to the vet and see the bills?
You may want to take this question to
http://www.petgroomerforums.com/chat/index.php
It sure will stir up the bee hive.
Frankly I don't believe her and would demand some kind of proof.
If all you say is true, then something is rotten in Denmark...