Since the system is designed explicitly to not allow remakes under the circumstances you describe, I took a look into your match history, theres only 2 remakes I can see in the past week or so.
In the first case from an hourish ago, your teams jg gave up first blood to the enemy adc (which wouldn't void a remake regardless for the enemy team), but their (sup? it's an odd comp) darius appears to have never connected in the first place, which is why remake was triggered. Even if the first blood went the other direction (so it would potentially void /remake), DCs that occur before the first blood are still eligible to trigger /remake.
In the second one from about a week ago, your teams mid lane and jg managed to get an early kill on the enemy mid lane, however again the enemy had an already afk irelia top, which is what allowed them to trigger /remake.
In neither of those cases the enemy jg dc'd in response to FB, so unless theres another case even further back, you're probably just mistaken about the cause of the /remake.
As for the screwed up swapping dc -> /remake, the person who dc'd still lost LP/mmr, so I feel like in most cases people would try to make it work rather than take a bullet for their team. Since they only have the brief window at the start of the game, they can't just be pressured into it by their teammates, so it's a rather selfless act I wouldn't exactly expect of the typical player. Meanwhile, 'free' wins aren't really supposed to be a thing either (as in if the game did play out), so it's probably appropriate for the sake of ranked integrity that things got remade. (I recognize 'ranked integrity' is still pretty questionable what with dynamic queue and premades, but it doesn't mean you should hope for stomps unrelated to player skill.)
