KJK appears to be going with the story that she scared him off.
Let's have a look at this assertion: he's a seasoned, experienced politician of a major party, with solid funding. Even suspended from the Labour party, he can still stand as an Independent. He only requires funding to campaign in his own electorate, but she needs to support her own Party.
In election season, it's common for allegations of this type to surface.They do need to be investigated, even if turns out they are vexatious. What if they are not? Additionally, If they were not investigated, you would be equally outraged with Starmer if LRM won and then it emerged.
KJK hasn't scared anyone, but she may yet have her opportunity.