We study the impact of DC power flow modeling in multi-leader single-follower market models on the AC feasibility of the market outcome. To this end, we consider strategically bidding power producers that are connected to an electricity network and a market-clearing executed by an ISO. The focus is on a pay-as-bid electricity market in which each producer provides the ISO with a bid used to derive its revenues directly, and the market clearing is performed by taking into account the DC power flow constraints. This scenario naturally leads to a multi-leader single-follower game in which the upper-level solution concept is a generalized Nash equilibrium among the power producers who are jointly constrained by the market-clearing process in the lower level of this bilevel game. While the accurate modeling of AC power flows is essential for system reliability and operational feasibility, its nonconvex nature poses immense computational and conceptual challenges for the bilevel setting. To address this, we propose a two-step approach. First, the multi-leader single-follower problem is solved using a DC power flow model for the lower-level market-clearing process using a diagonalization method. Second, the operational feasibility of the obtained production plans is evaluated by computing the closest AC-feasible dispatch. This quantifies how far the DC-based market outcome is from the closest AC-feasible dispatch. The approach is tested on established benchmark instances, and the main outcome is that DC-based market-clearing results have to be considered with great care when evaluated with respect to AC-feasibility.