Pakistanis seem to perform all kinds of mental gymnastics depending on the audience.Hangor didn't had bigger role to play than Ghazi.
The course of 1971 war would have been different in my opinion
1. Had PNS Ghazi not met the accident off the coast of Visakhapatnam.
2. Had Tejgaon not been neutralised.
3. Had Gen Niazi not decided to surrender despite having 20k to defend Dhaka.
PNS Ghazi had bigger role to play. Had it not met the accident it could had stopped the Naval Blockade of East Pakistan. Indians would have thought twice before bringing in INS Vikrant. Remember it was the same submarine used for Mumbai blockade in 1965.
Despite the heroics had PAF been able to secure Tejgoan for another week, Indian advance would have slowed considerably giving PA air cover and time for UN intervention.
Although East Pakistan was a lost cause, but had Gen Niazi decided to defend Dhaka with all remaining forces. A UN brokered withdrawal of Pakistan Army could have been negotiated thus avoiding surrender. Remember diplomacy takes time.
Despite all odds there is no denying of the fact that Pakistani forces put up an exceptional fight. Truth is India didn't win a war, all it did was to put an end date to a civil war.
To give comfort to each other they say India didn't win war it was putting an end date to civil war.
To give hate to Bangladeshis they say that Bangladeshis would have been able to do nothing had the Indians not showed up.
Amusing.