I am not the designer the original poster mentioned. However, I am in the design field and can provide some insight into your visit from the designer.
Many companies have design professionals that visit customer sites to learn about their tasks, environment, etc. This is part of "ergonomics" or the study of work. Ergonomics isn't just how people sit in office chairs or lift things, but about how the person interacts with their tools and their work environment. The designer was probably visiting to learn about the "ergonomics" of the job and to get your input as a subject matter expert regarding how a tool would be used within your environment. He or she knows certain design and human performance principles, but probably doesn't know how to do the work that you do. He visited you to get your input as to how you did your job. Smart companies are employing more of these professionals to help them develop more desirable products.
There are many types of user studies that companies undertake, but they can be categorized as either onsite studies, or field studies. In the U.S. it is customary to pay or compensate someone if you have them come to your site for a user study or interview, usually because they have to take time off work, travel to the site, etc. Also, the harder the job is to recruit for, the more the user is compensated. For example, if the company needs to speak with brain surgeons for a product they are designing, they will provide a higher level of compensation due to the rarity of brain surgeons and the difficulty in enticing them to take the time to come to the site for an interview or study. The more common the job and the larger the recruiting pool, the lower the compensation.
For some odd reason, field visits are not compensated at the same level that site visits are. In many cases, design professionals do field visits with users and do not provide any compensation. The design professionals often just watch the people work and ask them questions during the course of their day, so it isn't like the user has to take time off. I know it doesn't make a lot of sense, but in general people do not get compensated for a field visit unless they are visited at some really odd time or in a really odd location (like studying your family while they are watching TV after dinner). In the example of the brain surgeon above, if a designer were to observe the brain surgeon during an operation, the surgeon wouldn't be compensated by the interested company. A token gift may be provided to the surgeon for providing the privilege to watch something as guarded as a surgery.
Company culture may play into the level of compensation. Some companies are very generous with the different types of compensation. Other companies are not. It may depend on the product the company makes. Software is an easy to reproduce commodity, so expensive software is often offered as compensation for user study. A not so easy to reproduce item like a tool may be considered "too expensive to build" and not be offered. I guess it would depend on the products and company culture.
Also, as you may be aware, many companies are outsourcing positions and hiring contractors. I believe that Festool uses a contract agency to do their design work. This individual may have wanted to provide you something, but didn't have the authority to. Sometimes design professionals get placed in an awkward situation where the user wants something for their time, and the designer wants to thank them and accommodate them, but would need to do so out of their own pocket to do so. This may have been one of those cases. I know that I've bought many cokes for people in user studies because the company didn't have the foresight to provide drinks for their guests. I didn't get reimbursed. This may have been one of those awkward situations for the designer.
I hope this explanation helps.