KIM CUNNINGHAM :
I strongly advise you to put the plastic bolt back in. If you ever run into a dock or pier, or just an awkward beach landing, you will for sure do damage something else if the bolt is not allowed to break. I have broken several bumping into docks, and over achieving helpers but have never broken one while under way. If you go to the post (The ultimate Tandem Island (hydrofoils,Spinnaker,jib,etc) ( viewtopic.php?f=69&t=33720&start=45
) on page 4 there is an explanation on how to rig a safety rope that prevents the AMA's from folding in while underway, yet if you happen to hit a dock allows the sheer pin to break and prevent further damage. This simple rope only takes 30 seconds to install when setting up the boat, but it will for sure prevent any accident like you experienced from ever happening again. I use 1/4 inch dia stretchy nylon rope which work like a shock obsorber and is tied around the strongest point on the boat (the area around the mast is the strongest area on any sailboat). If I'm just going out in light air I don't bother putting it on, but any conditions or distance that is questionable or risky I install the safety rope. Like I said it is not intended to prevent the sheer bolt from breaking in the event you bump a dock or another boat, but will keep the AMA from folding in while sailing (turtle time), so you can safely furl the sails repair the broken pin then get back underway quickly. TI's come with a spare plastic pin right on the same bar right next to broken one. On the newest models they eliminated the plastic nut and replaced it with a cotter ring so if you forgot to pack your pliers (like I did) you don't have to use your teeth to get the replacement bolt unscrewed. To my knowledge you are only the second person to turtle a TI in over a year, the other guy had the same situation, He later thought possibly his sheer bolt was already damaged when he went out that day but didn't know it at the time.
Perhaps someone on the Forum can video themselves tipping and righting a TI and share it with the rest of us. I think someone posted that it is easiest if you fold one AMA in and bungy or tie in, then climb up on that AMA (obviously up onto the bottom of the overturned boat) grabbing onto the keel board then lean back and the boat slowly tips back up and over (being careful the boat doesn't hit you as it comes down , If the center board is on the wrong side and you can't reach it you can also throw the long sail line (the big black rope used to control the sail from either seat) over the bottom of the boat and use that to hold on to while you flip the boat (acts as a righting line). I have not tried it.
Hope this helps