Does it cancel the others spawn? Who gets priority and is money wasted? In a long match I playe I gained enough money to start spawning bots to aid the best chance we had to get to the money ball. A fellow sniper was doing the same and I noticed his bots spawned but not mines.
It probably goes to the person who had the better ping, which is usually the case for these "exact same time" moments. It might be like the Annihilator too, where you can spend money to activate it, but still get killed without doing so (in this case, not spawning bots instead of not getting the Annihilator.)
Back in the day, if you double-tapped the "Spawn Bot" button you'd get charged $200 for one wave of Bots. Due to my laggy connection, this was often a bad thing.
You'll never spawn them at the exact same time, so this isn't an issue. One of you will hit that button miliseconds first. Factor in lag, and there will be a clear first and second. At that point, whomever the server received as first spawns them.
Are you the same Runie I was playing with not too long ago? If I remember correctly you complimented me with "Nice shooting tex". And yes, that could possibly work, but it would still be hard to do it at the exact same time.