My film was X-rayed and I used it anyway

Online wisdom says, while airport security x-rays do minimal damage to film in hand luggage, checked bags get a larger dose of radiation that can be fatal for the film. Is this true?

On a return trip from the UK, my hand luggage was deemed it was too heavy by the staff. I repacked in haste. I realized I'd made a  mistake as our plane left the ground - I had put the film in the checked bag.

I was using HP5 which is a 400 speed black and white film. They were developed at home the usual way (read about my developing method here). The images are slightly lower contrast than usual, which might have made it more difficult to print in the traditional film days. But by scanning film we can easily salvage the negatives with software. They look as good as any other roll. 

Sowerby Bridge canal, Halifax. Hasselblad 500cm, Ilford HP5.