(sigh)
the 0.65v for PN junction IS the voltage drop across T1
Transistors and PN junction's and such active devices are usually not considered as resistances, except in special cases.
With the Collector & Base shorted, the effective part of this transistor is simply the Base - Emitter pn junction. almost exactly a diode.
the standard voltage drop across a silicon pn junction is usually taken in the range of 0.6v to 0.7v, and will not vary beyond these limits during forward conducting and reasonable currents.