GaAsFET amplifier connected with wrong bias polarity voltages

[afz23]

I am using GaAsFET amplifier FLC107 from Sumitomo,it requires -ve gate bias and +very drain bias voltages for its operation.
By mistake my technician reversed the gate and drain wires,i. e drain received -ve
and gate received +ve DC supply.-5v and +2v to be specific.
I thought device might have been damaged by reversing the polarities,but when
correct DC supply were again connected to verify,the device worked perfectly alright and drew the specified current.
I want to know the reason,still whether this device can be used with reliability in any application,or this device is degraded by reversing the polarity.

 

[BigBoss]

You'd better to change if it doesn't cost too much.Schottky diode at the gate may be damaged...

 

[biff44]

good engineers design reverse bias protection, for people like your tech

 

[afz23]

Biff44 can you please suggest reverse bias protection circuitry for high and medium power GaAsFET devices

- - - Updated - - -

Usually scottky diode at gate gets damaged at which positive voltage?
I am using a 10k series resistor with gate,may be this has saved my device.