Potty training #4; potty fear and losing the window

Potty training #4 started easy.  I thought he would be the youngest one trained.  He was a talker which made things easy and he had siblings using the potty.  Cocoa puffs was his little hero and he followed her everywhere.  He started at 16 months.  By 18 months he was pretty much day trained but occasionally needed a reminder.  He was also using the big toilet.  He was nervous about the big toilet and wanted me to hold both his hands.  I was OK with this.  It had been a smooth easy ride.

Then one day I was helping my dad and left the kids with their dad (I was married to a real arse at the time).  I told him about monkey #4, that he was nervous so please hold his hands and reassure him he would not fall into the toilet.  You'd think a dad would know this, but that's how little time he actually spent with us.

According to my daughters he was busy playing video games and told  Monkey 4 not to be a pussy and just go sit on the toilet.  Cocoa puffs went with him.  She was 3.5 and tiny, she was smaller then monkey 4.  He fell in the potty and Cocoa puffs couldn't get him out.

I came home to him still in tears.  He wouldn't sit on a toilet or potty.  There was a lot of tears and eventually I said he would need to go back in diapers and we would re learn when he was a little bigger.  By 2 I was trying again but we had missed the window.  He seemed to be completly un concerned.  By 2.5 we were still at it and failing.  At my wits end I started saying it was unacceptable.  Diapers are for babies.  And I gave all potty trained kids a treat at the end of the day for a day with out paccidents.  That worked and he trained with in the week.

I wish I had never left him with his dad.  I wish I had gently  insisted he face the fear and use the potty.  Missing the window was a nightmare and frustrating for us both.