What would Muhammad say about put-call parity?

Mahalanobis explains how Islamic mortgages are being created using put-call parity.  Islamic finance expert Mahmoud El Gamal sums up the situation nicely:

…I have shown in detail how to synthesize a forward from salam and a credit facility characterized as murabaha or tawarruq, depending on preference and cost. From forwards, we can then synthesize everything. That is a theorem.