Lost silver on bouncing an attack

I sent a hand cart of support ahead of an attack to bounce the silver so a friend could cap instead...the attack bounced, but my silver disappeared! What happened? I'm out 160k silver and not understanding why.

The hand cart came from an adjacent castle and easily arrived before the attack, so there's no chance that I made a mistake.

Did L&K change the rules on bouncing an attack?

Once a battle begins even for one second the troops you sent want their wages/ payment in silver

The support arrived well before the battle began ...I'm certain because the support originated at the closest castle on the map to the one being attacked.

Defender could have kicked the cart away

Defender was a friend who had gone inactive. I also verified that the cart was still there.