I've been flicking through The Silkworm, and noticed a bit where That Twat is thinking:
'...before she worked for Strike, Robin had always been first to back down in a row, first to apologise, but her conciliatory nature seemed to have been warped by the stupid bloody job...'
Which parallels one of my favourite descriptions of Strike's modus operandi in Troubled Blood:
'While Strike wasn't in principle opposed to offering an unsolicited apology in the event that he felt himself to have been in the wrong, in practice his apologies tended to be delivered late, and only when it became clear that resolution would come no other way.'
(I absolutely know men who operate like this. JKR nails it again.)
I love how both of them are being shaped unconsciously by each other and how their trajectories are crossing in the middle. Strike's apology is one of my favourite bits of TB, because Robin has been completely right in calling him out (and in refusing to get in contact first - she's come a long way from the Robin of The Silkworm), and he is able to respond to that by breaking deeply formed relationship habits. Admittedly his apology is not fulsome, but it feels genuine.