I'm almost done re-watching OPs cross examination.
At least as I'm hearing it, when he was first recounting how he moved along the passage to the bathroom, he had previously said that it was pitch dark in the bedroom. When Nel asked how he could see where he was walking, OP said he was able to make out the bathtub(?), faintly because the bathroom was somewhat illuminated by ambient light coming in from the outside.
At a mid-point in OP's testimony, Nel pressed him hard about the light again and how it had been seen on. He asked OP who had turned it on. OP denied it was him and denied it was Reeva. Nel then gave him the old, "Well, if it wasn't you and it wasn't Reeva, who did turn it on? ...
On the final morning of OP's testimony (4/15), Nel asked him, again, who turned on the light. Now, without skipping a beat, he said Reeva did. Nel asked whether she turned it on before or after she went into the toilet. OP said it was before. Nel, asked him again to verify that's what he said, and OP said straight out, again, that Reeva had turned it on and it was before she went into the toilet.
Beyond being so confused that he didn't know what he was saying, if he was tailoring this story, too, it would have been in the wrong direction, would it not?
Anyway, re-watching this after such a long time and knowing what I know , now, OP's detailed inconsistencies are much easier for me to identify.