Lost out on house due to sellers realtors mistake

We put an offer in on a house to which we lost out to a higher offer. Okay, that’s the game! Today our realtor found out we lost out because the sellers realtor didn’t execute our offer correctly and didn’t use the escalation clause which would have outbid the accepted offer. We have put in a backup offer. To say we are gutted is an understatement!

Our realtor says we have no recourse and to hope the deal falls through.

Would others agree?

I was wondering if anyone else has experience in a similar situation or if we are truly just out of luck!