It seems to me that all evidence points to Germans having no intention of killing all the jews in the beginning before the war and into the war.
Where cracks start to form is likely mid-war and at the point it started to become apparent that Germany was probably going to lose. I think some of the leadership may have suggested or attempted a desperation move of killing as many jews as they could knowing that they were going to lose. At least then, they'd have saved Europe from the jews they did permanently annihilate. I believe this idea was not unanimously agreed upon nor sanctioned by Hitler himself but was definitely a growing idea that was slightly spoken about but also unspoken among the leadership to keep a sort of "secret group" of hardliners that believed this was the better route to take. Hitler was somewhat aware of these headliners and their views but wasn't in a position to do anything about it even if he wanted too because his political capital mid-war to do anything about it wasn't there.
I think Hitler always intended to deport the jews and wasn't thinking with a mindset of losing the war so in Hitler's mind, the concentration camps were adequate but some of the other leaders doubted Germany's ability to win, like Himmler, & felt that keeping jews in internment camps was taking up too many resources so I believe some of Hitler's officers may have circumvented Hitler's commands to quietly kill jews instead of deport and/or keep them in internment camps. I believe these officers also felt by permanently ending these jews, it ensured despite Germany losing the war, that perhaps it wouldn't becomes judaised (of course, this didn't happen but I can see how one might think this before Germany had lost if you felt the jews were ultimately the problem).
I think the number 6m is pure fiction and the 200,000 seems a lot more reasonable as a number of jews who died. Not all of them would have been killed by Germans intentionally but from starvation and sickness due to a lack of supplies during the war.
Overall, there was definitely some intention of higher up officers to kill all the jews but that sentiment wasn't necessarily shared among all leadership and never directly ordered. In the chaos of the war some high ranking Germans definitely did kill jews intentionally but many also died from sickness and hunger due to a lack of resources. The total number of jews who died is closer to 200,000 instead of 6,000,000.
Thoughts?
There were some like particular incidents where with the evidence we have you could infer that they probably did have some small scale executions but it wasn’t like a government directive, if any orders did come they would have come from Himmler, not Hitler, but like you mentioned even in the particular incidents it was just live wire officers, not like top level orders. When I say “with the evidence we have” he goes over how, I don’t think there are any documents that actually show direct orders for executions, I think you literally can only just make the case in a tangential manner like “the prisoner count dips in this report after the last one” and stuff like that. And it wasn’t even huge numbers for any given event compared to what we’re told. He went over this one piece of evidence which was basically the most concrete case you could make for Himmler giving an order to execute some prisoners but even that it wasn’t direct proof you had to infer it and it wasn’t conclusive.
If I remember correctly in that lecture Irving gave his own speculative estimate for the total Jews that were killed and I think he had some other sources and kind of ball parked a number and it was more than the Red Cross report, it may have been like 400k or something. That was with like exhaustive research beyond just the regular sources but it was also him being generous like giving them the benefit of the doubt in every case and it still was something like 400k.
It doesn't shock me that Irving speaks specifically to Himmler, he's a key piece in the holocaust narrative.