Not a wood flooring expert - however, I do know a few things about hardwood flooring.

First - what is your subfloor? If there is moisture in the subfloor (for example, if it was installed over concrete), it can transfer to the wood floor which will lead to swelling and buckling. My installer took moisture readings of my subfloor (plywood) and of the wood planks prior to starting in order to make sure that the two woods were within the required range.

Second - was a sufficient space between the boards and the walls left to allow for the wood to expand? If not, the boards will buckle as the expand. Sometimes an inexperienced installer will butt the boards up against the walls leaving no room for normal wood expansion.

Third - you've stated that the boards were in the house for five days prior to install. For solid oak floors, I was told that the boards should be acclimated for at least a week. However, a professional will be able to let you know if the wood should have been allowed to acclimate longer. Do you know how long the manufacturer required the boards to acclimate prior to installation?

Fourth - my understanding is that an uneven subfloor may cause buckling. If the subfloor wasn't properly prepped prior to installation, you may wind up with issues.

I'm sure there are other reasons - these are just the ones that I know.

Regarding the rough spots on the ends of boards - did you see the ends prior to installation? Did you source the flooring? I assume that if the boards were sourced from a low end source (I've read posts where the OPs had issues with floors sourced from Lumber Liquidators - I'm sure that there are other places that should be avoided also).

Also, movement of improperly installed boards may cause splintering due to rubbing when movement occurs.

I assume a pro will jump in shortly and provide some expert opinions + advice.

Subfloor, oriented strand board (OSB) over a crawl space. Underlayment was put down prior to installation. The subfloor was even. Flooring purchased through flooring company, Somerset red oak.

I'm going to go out on a limb and guess that you do not have buckling, since you posted no pictures of buckling.

From the few pictures you did post, it appears that you have prefinished Somerset Red Oak flooring, possibly solid. These pictures seem to show a bit of lippage, which wood pros often call over-wood. Since the floor appears to have eased edges and square ends, it's not unusual for some of the ends to have lippage. It's illogical to expect a natural material that moves to remain perfectly flat, but there is a limit of allowable lippage. Speak to your installer to see what they can do.

And if you actually do have buckling, post better pictures, because that would be a much more serious issue.

Zooming into the pictures, can notice some hammer marks, specifically the second photo. A disadvantage of prefinished floors, the finish is brittle and can damage very easy during installation. Wipe it with a damp rag, the crushed fiber will lift up. If, it is a hazard, have the board replaced.

"If it is a hazard, have the board replaced."

And if you do so, note that most of the tongue and groove will have to be removed, making it far more likely that you'll have pieces that don't line up at the edges.

OP- was this product indeed prefinished solid hardwood? I was considering it for our new build but now this causes me to reconsider it.