Was the BA038 jammed by Gordon Brown's motorcade?

I was informed about one of the most intriguing theories heard so far dealing with the BA038 crash landing, by Scott, a visitor who wrote an interesting comment on one of my previous posts dealing with the G-YMMM accident. Here’s Scott’s comment:

Prime Minister Dr. Gordon Brown’s motorcade was passing under the approach path of BA038. His security system utilised a RF transmitter to block out any cell-phone triggered devices. Apparently this system has a two mile range, and it caused the Boeing 777 EEC’s (electronic engine controls) to sense a “overboost” situation, thereby commanding a reduced-thrust situation for the engines, simultaneously.

Even if the final report was not issued yet (at the moment, there’s no confirmation about the possible interference by the AAIB) this theory focuses again on an EMI (Electromagnetic Impulse) as the cause of the crash landing of the British Airways B777. It must be remembered though that the initial reports don’t say anything in particular about possible intereferences: “The autopilot and the autothrottle systems behaved correctly and the engine control systems were providing the correct commands prior to, during, and after, the reduction in thrust”.
It is possible that Gordon Brown’s motorcade use electomagnetic signals to jam remote controllers, mobile phones and other wireless devices. The cellphones are in fact used to trigger bombs and jamming can prevent them from sending input signals to remotely activated bombs. Such a risk is concrete and, for example, in 2005, during the Rivolto Open Day in Italy, for a certain period of time, all the cellphones in the airport and around were prevented from connecting to the GSM network (switching off the local cells in that case) as a security measure against terrorist attack that could be planned against Italian Prime Minister, Ministry of Defense and many authorities and VIPs that were attending the Air Show. I don’t have any idea about the power, frequencies and range of a jamming system like that one used (if used) by the British PM’s motorcade and if it can interfere with the aircraft systems. What made me think is that the jamming system caused problem to the landing 777, it should have interfered with other aircraft’ systems and with many electronic devices nearby. Furthermore I don’t know if this system is always switched on when the motorcade moves because if so, there would be many reports of interferences in and around London. For sure, jamming exists and it can have cause some troubles: a few years ago, an alleged signal emitted by ECM equipment at Nellis AFB (even if this thing was never officially confirmed), affected remote controllers, garage openers and remote door openers for automobiles in the Las Vegas metropolitan area. If the AAIB report will point to the jamming as the root cause of the BA 038 accident, there will be a serious reasons for studying in detail how to shield aircraft systems better to resist to accidental (like the presumed one on Jan. 17) and/or intentional jamming of commercial flights (but not only) departing and landing from civilian airports.