Disagreement on buyer's realtor fees. How can we remedy this situation with our realtor?

In hindsight, there were a few mistakes made here - but I'd like to get some opinions on how this could've been worked better, and if there's any hope for a happy situation for everyone.

There are three parties involved here..

• Me
• Friends
• Mutual Aquantiance / Semi-Friend we both know from common social groups. I know them better than the friends.

Friends have been looking for a place for a while - but not necessarily in a rush. I've been doing most of the searching, picking out open houses, etc. They wanted a place, but not "spend serious time with a realtor" wanted one. If one happened to show up then they were ready to hop on it.

One showed up. We all saw it (still no realtor in the picture) and said this is the place! Great! We know our realtor mutual aquatianence, let's call them.

Stuff moves quickly in this area - from listing to accepted offer is usually within the week, so we called them up and started to talk. In the rush to get paperwork going we were convinced by the realtor that their 3% commmission rate is the standard and no worries, it'll be paid for by the seller anyways.

Stuff gets signed and an offer gets submitted.

The seller's realtor is getting paid 2.5% and the seller is saying they won't cover more than 2.5% for the buyer. My friend's realtor, now that we're stuck with them, says they have to cover the remaining 0.5%. This amounts to a few thousand dollars out of their pocket.

I feel misled, foolish, embarassed, and somewhat betrayed here.

We didn't dig deeper into the local area's averages for realtor's commission. It does tend to be more closer to 2.5 than 3%.

I (+ friends) trusted the realtor in that the 3% was normal, and in the rush to get an offer out soon given the speed of the market, didn't give ourselves time to negotiate that.

I feel like the job of the buyer's realtor is at least 50% dealing with indecisive clients, finding listings, showing them, etc. In contrast here we basically handed her most of the deal on a silver platter. Here's the place, financing already secured, lawyer already contacted, let's go. Am I wrong in thinking this is like the easiest commission ever?

The "Mutual Aquantiance / Semi-Friend" is taking the stance of "well too bad, we signed a contract you owe me the difference". They're not wrong, but am I also justified in feeling misled and betrayed here?

I feel like a terrible friend too, in that I helped my friend find this place after maybe 1-2 years of "hey let's go check out this open house!" or "what do you think about this new place that just showed up on Zillow?" that we DID find a place for them, and then inadvertently "gifted" them unnecessary realtor fees. It was my idea to call up the mutual aquatianence after all.

Given all of the above - How can this end in a way that leaves everyone feeling no ill will against each other?