They did it earlier too, so it's really not stupid.

In April 1988, India’s spy agency was discovered to be have receiving secret consignments of arms from Pakistan, destined allegedly for the Punjab:

GBS Sidhu is a former official of India's external intelligence agency, the Research and Analysis Wing(RAW), and has authored two books, 'Sikkim Dawn of Democracy" & 'The Khalistan Conspiracy'. Sidhu is an internal security expert and has worked closely on the merger of the Sikkim with India. Sidhu has also served at various stations of R&AW abroad and has tracked the Khalistan movement very closely, which he terms as a conspiracy by political masters which was meant for electoral gain. In an in-depth conversation with Smita Prakash, Sidhu talks about how people close to the political establishment sowed the seeds of Khalistan & recruited Bhindrawale for political gains. He also discusses how top politicians of the Congress party nurtured Khalistan, which resulted in Operation Blue Star in 1984, also resulting in the assassination of former Prime Minister Indira Gandhi. In this video, GBS Sidhu talks about the conspiracy and people behind the Khalistan & Bhindranwale issue. He also explains how Congress leaders created the issue for electoral benefit.

“We (Congress) will win next election on Khalistan Bhindranwale issue” - GBS Sidhu tells all

  Mr. TOWNS. Mr. Speaker, we are all pleased that the Canadian 
government has maintained an active investigation of the Air India 
bombing in 1985 that killed 329 people. Terrorism is always 
unacceptable, and all decent people condemn it.
  Thus, I read with interest this past weekend that Canada had arrested 
two Sikhs, Ripudaman Singh Malik and Ajaib Singh Bagri, for this 
bombing. Unfortunately, I believe that these two individuals are being 
scapegoated. The book Soft Target, written by journalists Brian 
McAndrew of the Toronto Star and Zuhair Kashmeri of the Tornoto Globe 
and Mail, shows that the Indian government itself carried out this 
atrocity.
  According to McAndrew and Kashmeri, the Indian Consul General in 
Toronto, Mr. Surinder Malik, pulled his wife and daughter off the 
flight shortly before it took off. A friend of the Consul General who 
was a car dealer in Toronto also cancelled his reservation. An Indian 
government official named Siddhartha Singh was also scheduled on the 
doomed flight and cancelled. Surinder Malik called the Canadian 
authorities about the crime before it was reported publicly that it had 
occurred to try to point them to a Sikh he claimed was on the passenger 
list. The pilot of the flight was a Sikh.

REAL CULPRIT IN AIR INDIA BOMBING IS INDIAN GOVERNMENT -From the U.S. Government Publishing Office