Bertie - you are right, of course, but it's nonetheless true of some men that they seem unable to anticipate danger. DH is one. The only danger he was ever bothered by was that DS would be scalded by boiling water, as DH had been at school with a child to whom that had happened, and seen the resultant scars.
However, most of the time I could point the potential dangers out to DH - but not always, frequently I was mocked for my "fears" - until the time that DS was nearly drowned while out in the lake with MIL, because she lost her footing. I'd TOLD them both that they weren't to take him in the lake, DH because he doesn't think, and her because she's not safe on her feet - and there you go. Luckily DH turned round in time to see DS above the water but no sign of his mum (she was underwater, holding DS up) and jumped in and saved them both - but it was a near thing! 
Equally, when we got a trampoline for DS (with a net) I wanted to put it onto the grass so that if anyone fell off, it wouldn't be so bad. DH thought I was silly, didn't want the grass ruined, so put it on concrete. Within the first week, Ds had fallen through the open zip in the net (DH hadn't bothered to close it) chin first onto the concrete. LUCKILY (oh so very!) he wasn't that damaged, just had a great big open flap of skin on his chin that I cleaned as best I could and then steri-stripped back together, went to the doc 2 days later (BH weekend, of course) to get it checked properly. He has a very minor scar there now but he could have broken something, concussed himself, anything.
Of course, DH is now absolutely on the ball about potential drowning, falling out of the trampoline etc. - but he'd been completely unable to anticipate those accidents because he doesn't think it will ever happen.
We won't even go into the stolen car that didn't have full insurance on it...