What GOOD reason would a home buyer have to speak direct to seller?

Tell the broker that Eric is a very friendly, old-fashioned sort who likes to talk to people. Then tell him that Eric just wanted to chat about what the neighbors are like, what the neighborhood is like to live in, just get a sense of things - nothing very critically important.

Don't overthink it. Just tell him Eric had some questions, you're not sure what, no big deal, but now you realize that buyers and sellers shouldn't meet and you won't make that request again. Dude, buyers and sellers shouldn't meet unless you're buying without an agent. There are very good reasons for this, mostly related to the fact that people are weird about money and sentimental about homes. And also crazy. I was a potential buyer in a situation where the seller wanted to personally meet and approve the buyer of his beloved home. Seller's agent tried everything to talk seller out of this but he wouldn't budge. We agreed to meet. Things got weird and we walked away. Wouldn't do it again, don't recommend. The agents are there to ensure a business transaction happens without weird illogical shit that people spending their entire savings or selling their childhood home can bring into it. Make sure Eric knows this. I say all this as someone who has happily bought and sold real estate, both with and without agents, and who used to believe real estate agents services were overrated. But having experienced crazy first hand, I suggest that you and Eric get on the same page and don't be the crazy.

I'd like to know what to say to the broker when I next speak to him as to why "we" wanted to to discuss directly with the seller rather than with him. If it were me I think I'd just say that you had a question you wound up answering yourself. But it may just be that Eric wanted to just ask a bunch of questions and didn't really know that it's usually not done to speak with the seller directly or he's trying to get you be pushy for him and knows he's being pushy. Brokers are worried they will be cut out of deals somehow or that sellers will sabotage deals, and sellers want to be protected from weirdie buyers. Buyers want as much information as possible so there are a bunch of reasons a buyer might want to talk to the seller but I'm not sure how much they are all characterizable as "good reasons". I don't know how well you two know each other, but your anxiety about being the go-between here may make you not a great go-between if you're not comfortable either getting vague answers from Eric or not coming clean with the broker. Because it's totally okay to just say "The guy I'm looking to buy with requested this, I don't know why, but then he said he didn't have questions for you" and just leave it. You can continue to work with the broker and just not work with Eric.

Perhaps Eric is suspicious that the broker will spin the answers to any questions he asks on your behalf. (I'm sure they do with soft stuff, but they could get in big trouble be misrepresent ing hard facts.)

If in fact, Eric did want something out of the meeting or has doubts about the broker's ability to negotatiate the best deal then he needs to share his thoughts with you so you two can figure out if there is a way to get what you/he wants. But, if Eric is saying "never mind" let's assume the best. Eric wanted to meet the seller because he thought it was the right thing for a buyer to do or because he preferred to meet the person who he was buying from. (Both reasonable ideas about the "right" way to buy a house if you hadn't done it with brokers before.) When he got called on it, he realized that there wasn't anything specific he needed to ask and was embarrassed and backed off. I would tell the broker, Eric was interested in meeting the seller in person but if that is a problem it is not a big issue.

Our buyer wanted to know about the neighborhood, from the perspective of someone who had lived there a good number of years. We didn't meet, but we did answer some written questions. Your relationship with Eric sounds like a different question.

I thought of getting into that, but since it didn't really have to do with the question I wasn't sure it would make the posting too long. I've known Eric for many years and he owns properties already (I do not). He mostly got these properties via inheritance, so he didn't purchase them himself, but I was there when he fixed a couple of them up and has maintained the properties well over the years. Despite his weird behavior at times (I suspect he may have Asperger's) he does have excellent financial credit and history with his properties. If I go on my own it will be a few years before I can proceed, but with him I can move forward now.

Eric may have been trying to work out an under-the-table deal directly with the seller in order to cut out commissions for buyer's and/or seller's agents, which would likely violate at least the contract the seller has with his/her agent. Or he may just have been trying to cut through the bullshit relay to negotiate in real time. When I bought my current house, after three previous failed offers on other houses, I negotiated directly with the seller's agent because it was faster than relaying every message through an extra party, but only because I felt comfortable doing so after seeing how the process works a few times.

Meeting the seller is entirely normal / expected in most parts of Europe. There is always the possibility that you love the property but not the seller, but if the vendor (or buyer) is crazy there is a lot to be said for finding that out before you get entangled in a major financial transaction with them. So to answer your question, just say that Eric is accustomed to the European way of buying property.