some people just go into denial if something like that (that is likely to kill you) happens
In other words, they lie to themselves.
others just completely get blocked mentally and don't dare to tell the truth because they know what will then happen.
In other words, they lie on purpose.
people don't always lie because they're evil masterminds bent on infecting the world.
No. They lie because they're selfish assholes who don't give a fuck about anyone else (including their own children in this case).
Nothing you've posted contradicts your parent. The man lied and endangered the lives of others in the process. All of that is a matter of fact. Why he did it is mostly irrelevant, but since you brought it up, I'm gonna go with the selfish prick theory.