the tenor of the OXX letter to the OIP directors says to me that...

the tenor of the OXX letter to the OIP directors says to me that OXX is positioning a challenge to the court, in the event of the Scheme being approved.
Once the OIP s/h vote, if the OIP s/h actually do approve the Scheme at the EGM, then OIP must take those results back to court and ask the court to approve the Scheme.

It's a London to a brick, that if OIP s/h approve the Scheme, that OXX will challenge the vote in Court, based on those arguments they have detailed in that letter to the OIP directors.

OXX will be using those arguments (and the prospects of a challenge) to persuade the OIP directors to postpone the vote.

As a seperate issue, the OXX offer effectively is a defacto capital raising for OXX - it offers OIP s/h OXX scrip, and in return gets $11m of OIP cash (plus whatever other assets eg permits etc).

Also I think OIP can feel comfortable that the OXX offer and the Scheme vote, are not interdependent.
OIP s/h CAN REJECT BOTh if they desire.
To reject the Scheme, they also can reject the OXX offer.

Whatever happens, this fracas is going to focus everyone's attention on the value of OIP - so OIP may well come out way ahead of where it was earlier.

cheers