OpenWRTInvasion is used to get root-shell access so you can flash OpenWRT in a relative easy way.
So access to kernel log should be possible and the stock firmware looks to be some sort of heavy modified OpenWRT (some early 14.07 based on kernel log posted on the openwrt support page for this router)
Ideea is to at least see how partition table looks like and either confirm it's the problem (or at least one of the problems) or plain realise it has nothing to do with the brick reason. 
And he/she doesn't need any other hardware to do it.