I believe the scene in question is a fabricated conversation, or at least heavily altered by the situation, as memories are a fickle thing, its like a text doc that gets edited every time its accessed. Given everything we have seen with how Hamish and Marrow act they clearly love their son, they definitely have asked if they are good parents or if they rushed into things to fast and likely its one of those conversations that's being altered in that memory (they talk about a lot of things that Cole would not have known had he overheard this earlier, such as Marrow's history, something we know Cole is curious about as his papa doesn't talk about his history). We have seen that there is definitely problems with the bonebreaker household, but a lack of love is not one of them, there is an imbalance in the co parenting responsibilities (marrow refuses to be anything other than the fun dad, and admits as such in an earlier chapter, putting a lot of the brunt on Hamish to actually raise their kid), and Hamish is rightfully called out on his hypocrisy on wanting Cole to come clean about magic, though that mess is thoroughly a hell of marrows own making and is something they are all going to need to come clean on as we know marrow has a history in a noble house all about magic. We know Hamish has very complicated feelings about family, he is someone who is terrified of being abandoned and unwanted so Cole has been a extremely difficult child for him, though he still goes far above and beyond as a father who wants his son to love and accept him. Pardon my ramblings, though I hope they provide some insights.
Edit: also given that the two memories that are shown surrounding it, the first is based on real events though exaggerated by Cole's self-loathing, and the third is a fear of what could be, it would be odd if the second one was fully real.