1. We didn't look hard enough before. Improbable
2. The outflow is high beta and does not make an MHD shock. Very unlikely, the loops are certainly low-beta
3. The reconnection outflow is not superalfvenic. Complicated, but possible (cf. McKenzie and Hudson 2000)
4. (My favorite) The plasmoid reconnection scheme does not explain the impulsive phase at all.