Should I be expecting this often or...?
Level 65? I suppose you modified the research gain curve and/or started at a much higher tech level than default?
Just to be clear about this, the AI isn't crazy - it merely attempts to build things in as great number and size as possible, which means that ships will get ridiculously large if you increase the tech level that
much. Something like 20-25 should be the absolute practical limit in a normal game, much more isn't normally achieved. So no, you shouldn't be expecting this to happen often (unless the aforementioned situation happens again).
P.S.: Welcome to this forum!