In the Thunderbolts crossover issue they showed that Deadpool came and saved Taskmaster and then both of them fought with the Thunderbolts. The fight ended when Deadpool got his head chopped off. The end of the issue showed Deadpool (with his head sewed back on) at an ATM with Taskmaster so that he could pay him (by using a credit card he stole from Osborn). Deadpool asked Taskmaster how he got away from the Thunderbolts and Taskmaster said that he was fighting Ant-Man, so it really wasn't that hard.
The funny thing is that in the issue Taskmaster was disguised as a Deadpool decoy the whole time, so I don't think Osborn even knows that the guy he's putting in charge of stuff over in Avengers: The Initiative is the same guy who was helping out Deadpool.