Sorry to hear about your unscheduled dismount. I, too, am a big fan of having a horse who can be mounted/dismounted from either side. Have had really bad knees at times in the past, which mean that I can't dismount without doing exactly what Foxhunter described - right leg over, hold tummy/ribs on saddle, kick left foot out of stirrup and sliiiiiiide down to ground or mounting block. Also, I wholeheartedly agree with Stan about a breast collar or breast strap, whatever they are called in Canada. I happen to have a brand new one, I think (black, nylon/felt which would match your saddle) that was sent to me in error with an order a few years ago - if shipping isn't too much to Canada I would be happy to ship it to you, as I don't want to bother trying to sell it. It would hold the saddle from slipping quite as easily, which is an extra bit of insurance for you in the dismount. Just let me know if you'd like to have it!
Best birthday wishes to Marc, are you stirring up something special for his dinner?
Foxhunter, Star the (Stinker) Pony was much less ouchie today. Did a fine job with the little kiddos on lead line, hubby said he wasn't keen on trotting but when he did, I saw no lameness. Thanks for your suggestion to identify shoulder alignment issues! I hadn't heard of that before but it is very good to know!