[Altaïr will not be caring for a lizard in his elder years if that turns out to be the case, but it's probably not worth getting into an argument with Hilda about looking after their lizard children for unknown spans of time. (Even if his side of the argument would be right. Children are meant to leave the nest eventually.)]

Circulatory and respiratory, according to the experts' assessment.

[Which may or may not be correct, but it's not as though he and Hilda have the knowledge to argue.]

And I doubt that reason was either a special fondness for or dislike of this particular lizard.